A retrospective clinicopathological study of erythema nodosum

Erythema nodosum (EN) may be idiopathic or secondary, and usually resolves naturally within 1-2 months. In atypical EN cases, the rash extends beyond the lower limbs to the upper limbs and trunk, and histopathological findings may be accompanied by vasculitis in addition to septal panniculitis. Few studies have examined the differences in the clinical characteristics of patients with EN based on rash distribution. We retrospectively examined whether there was a correlation with clinical information, such as the presence or absence of underlying diseases, by classifying the patients into two groups: the lower limbs group (the EN rash was confined to the lower limbs) and the beyond lower limbs group (the EN rash appeared beyond the lower limbs). Among the 86 adult patients diagnosed with EN at the Dermatology Department of Fujita Medical University between 2015 and 2020, there were 65 cases of the lower limbs group and 21 cases of the beyond lower limbs group. The frequency of underlying diseases was significantly higher in the beyond lower limbs group (76.2%, 16 cases) than in the lower limbs group (40.0%, 26 cases; P < 0.005). Vasculitis was more notable in the beyond lower limbs group (P < 0.05). Significantly higher vasculitis was noted in the EN group with underlying diseases (30.2%, 13 cases) than in the idiopathic EN group without underlying diseases (11.6%, 5 cases; P < 0.05). Neutrophil extracellular traps were positive in approximately 40% of cases in both groups. In the beyond lower limbs group, the possibility of severe cases with underlying diseases, vasculitis, and inflammation must be considered for effective treatment.

Pancreatitis, Panniculitis, and Polyarthritis Syndrome as the First Symptom of Necrotizing Pancreatitis

Pancreatitis, panniculitis, and polyarthritis (PPP) syndrome is a very rare cutaneous manifestation found in patients with acute pancreatitis. We report the case of a 44-year-old man presenting with erythematous, painful lesions on the lower extremities and ankle swelling. The rheumatology service was consulted for possible erythema nodosum. Extensive workup revealed elevated lipase and amylase levels, and computed tomography of the abdomen and pelvis revealed acute pancreatitis with necrotizing lesions and peripancreatic thoracic collections. There were also changes of chronic pancreatitis. The original skin manifestations were eventually identified as pancreatic panniculitis by skin biopsy. The patient was treated for pancreatitis and pleural effusions, and his skin and joint symptoms completely resolved. Pancreatic panniculitis with polyarthritis is rare but may be the first presenting symptom of pancreatic disease. Rheumatology may be consulted for these patients especially if there are only skin and joint manifestations and no abdominal pain. Misdiagnosis of pancreatitis can lead to poorer outcomes and delay in care. Therefore, pancreatic disease should be on the differential for any patient with panniculitis and polyarthritis.

Characteristics of Patients With Alpha-1 Antitrypsin Deficiency From Rural Appalachia: A Retrospective Single-Center Study

Alpha-1 antitrypsin (AAT) deficiency, an autosomal co-dominant inherited condition, significantly impacts lung and liver functions, with mutations in the SERPINA1 gene, notably the Z allele, playing a pivotal role in disease susceptibility. This retrospective descriptive study from a rural Eastern Kentucky pulmonary clinic aimed to characterize patients with AAT deficiency, focusing on demographic, clinical, and laboratory parameters extracted from electronic health records (EHR) of Appalachian Regional Healthcare (ARH). Among 100 patient encounters, 56 were analyzed, revealing notable sex-based differences in smoking rates and co-existing conditions, with males showing higher rates of black lung and chronic obstructive pulmonary disease. In comparison, females exhibited higher rates of asthma, COVID-19, pneumothorax, and obstructive sleep apnea. The study emphasizes the importance of understanding genotype-phenotype correlations and demographic factors in assessing AAT deficiency, advocating for further research to refine management strategies and elucidate causal relationships.

Nodular vasculitis (erythema induratum) associated with systemic minocycline

A 29-year-old Caucasian woman presented with a 3-month history of bilateral lower limb swelling with painful erythematous nodules on shins without ulceration. She had been taking minocycline for acne vulgaris for 3 years. Biochemical investigations showed deranged liver function test with positive ANA and mixed antinuclear factor (ANF) pattern. A skin biopsy was in keeping with a diagnosis of nodular vasculitis. Her skin lesions and liver function test improved within 3 months of stopping the minocycline treatment. This case report raises the awareness that minocycline could be a potential cause of nodular vasculitis, patients on minocycline should be closely monitored and minocycline should ideally not be prescribed for more than 12 weeks, given the possible adverse effects.

A case of anti-SAE1/2 antibody-positive dermatomyositis with extensive panniculitis: A possible cutaneous manifestation of treatment resistance

Dermatomyositis constitutes a heterogeneous group of autoimmune inflammatory conditions with a wide variety of clinical outcomes. The symptomatic heterogeneity carries skin, muscle, and joint manifestations; pulmonary and cardiac involvements; and concomitant malignancy. Any of these symptoms often appear at different combinations and time courses, thus posing difficulty in early diagnosis and appropriate treatment choice. Recent progress in laboratory investigations explored the identification of several myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies, allowing precise characterization for a clinical perspective of the disease. MSAs can be detectable in approximately 80% of patients with whole dermatomyositis, some of which closely reflect unique clinical features in the particular disease subset(s), including the distribution and severity of organ involvement, treatment response, and prognosis. However, only limited evidence has been available in dermatomyositis-associated panniculitis, mostly that in anti- melanoma differentiation-associated protein 5 antibody-positive disease. We present a rare case of a patients with dermatomyositis with extensive panniculitis on the trunk whose serum IgG autoantibodies reacted with both subunits of small ubiquitin-like modifier activating enzymes (SAEs), SAE1 and SAE2. The onset of panniculitis coincided with increased disease activity, including disease-related skin manifestations, fever, dysphagia, and muscle weakness in the extremities. These symptoms responded well to a high dose of systemic steroid, but even upon receiving a high-dose intravenous immunoglobulin, the panniculitic lesions and pruritic erythema flared with tapering of steroid dose, further requiring tacrolimus and mycophenolate mofetil to achieve disease remission. To our knowledge, this is the third reported case of anti-SAE autoantibody-positive dermatomyositis with panniculitis. We aim to extend the understanding of the current limitation and further perspective in the clinical management of the extremely rare skin manifestation associated with dermatomyositis.

Idiopathic Isolated Mesenteric Panniculitis: A Case Report of a Rare Adipose Tissue Disease

Mesenteric panniculitis belongs to a spectrum of rare diseases affecting the fatty tissue of the mesentery. It is characterized by chronic inflammation and fibrosis of the mesenteric adipose tissue of the bowel. Patients typically present with symptoms such as abdominal pain, nausea, vomiting, anorexia, bloating, and weight loss. Computed tomography (CT) is commonly used for diagnosis in most cases. We present a case of a 42-year-old male who experienced a significant escalation of abdominal pain over a 24-hour period. Despite seeking medical care at multiple hospitals and being prescribed analgesics, his pain remained unrelieved. Based on CT findings and the worsening pain, mesenteric panniculitis was suspected, leading to a diagnostic laparoscopy that confirmed the diagnosis. The patient was treated for idiopathic isolated mesenteric panniculitis during his hospital stay and was subsequently discharged. This article emphasizes the importance of considering mesenteric panniculitis as a possible differential diagnosis in patients with nonspecific abdominal pain, to avoid overlooking this condition.

Löfgren Syndrome: A Mosaic of Sarcoidosis Phenotypes

Sarcoidosis is an autoimmune multisystemic granulomatous disease with an unknown etiology. Löfgren syndrome (LS), an infrequent initial presentation of acute sarcoidosis, is characterized by the classic triad of acute arthritis, erythema nodosum (EN), and bilateral hilar lymphadenopathy (BHL). The presence of this triad offers high diagnostic specificity for sarcoidosis, eliminating the need for a confirmatory biopsy. Typically, LS follows a predictable, self-limiting clinical course. However, atypical presentations require early suspicion and closer monitoring. This case report highlights an unusual clinical manifestation of LS, marked by an incomplete presentation with acute panniculitis and joint lesions in the absence of EN. Acute sarcoidosis should be considered among the differential diagnoses when these clinical manifestations are present, and chest radiography should be performed to rule out BHL. In atypical cases, the disease course becomes less predictable, as exemplified in our case, where recurrence of the disease may occur, necessitating consistent monitoring.

Common superficial and deep cutaneous bacterial infections in domestic animals: A review

The skin covers the external surface of animals, and it is constantly exposed to and inhabited by different microorganisms, including bacteria. Alterations in the skin barrier allow commensal and/or pathogenic bacteria to proliferate and penetrate deep into the lower layers of the skin. Being the first barrier to the external environment, the skin is prone to injuries, allowing the penetration of microorganisms that may lead to severe deep infections. Companion animals, especially dogs, are prone to bacterial infections, often secondary to allergic dermatitis. When environmental conditions are unfavorable, horses, cattle, sheep, and goats can develop superficial infections, such as those caused by Dermatophilus congolensis. Deep inflammation is commonly caused by Mycobacterium spp., which results in granulomatous to pyogranulomatous dermatitis and panniculitis. Likewise, bacteria such as Nocardia spp. and Actinomyces spp. can cause deep pyogranulomatous inflammation. Bacteria that lead to deep necrotizing lesions (eg, necrotizing fasciitis/flesh-eating bacteria) can be severe and even result in death. This review includes an overview of the most common cutaneous bacterial infections of domestic animals, highlighting the main features and histologic morphology of the bacteria, cutaneous structures involved, and the type of inflammatory infiltrates.

Panniculitis: A Cardinal Sign of Autoinflammation

Panniculitis was first described in the nineteenth century and is characterized by inflammation of the subcutaneous fat. It may be categorized in septal or lobular subtypes, but other histopathological features (e.g., presence of vasculitis, nature of inflammatory infiltrates, characteristics of fat necrosis) are also important for diagnostic purposes. Clinically, panniculitis is characterized by the presence of subcutaneous nodules, and both ulcerative and nonulcerative clinical subtypes have been proposed. In this review, we aimed to describe the occurrence of panniculitis in autoinflammatory disorders (AIDs) and related diseases. Among monogenic AIDs, panniculitis is common in IFN-mediated disorders. Panniculitis is a distinctive feature in proteasome-associated autoinflammatory syndromes (PRAAS), including chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE) syndrome and Nakajo-Nishimura syndrome. On the other hand, erythema nodosum corresponds to the most common clinical form of panniculitis and is common in polygenic AIDs, such as Behçet's syndrome, inflammatory bowel disease, and sarcoidosis. Cytophagic histiocytic panniculitis, lipoatrophic panniculitis of children, and otulipenia are rare disorders that may also present with inflammation of the subcutaneous fat. Therefore, panniculitis can identify a specific subgroup of patients with AIDs and may potentially be regarded as a cardinal sign of autoinflammation.

A case of progressive crossed hemiatrophy mistaken as panniculitis

Progressive crossed hemiatrophy is an extremely rare clinical type of facial hemiatrophy that presents primarily as unilateral facial atrophy and contralateral trunk or limb involvement. The undistinguishable clinical manifestation and pathological changes complicate diagnosis, especially at the onset of the disease when presenting with less clinical evidence. Here, we report a case of a 9-year-old boy started with left scalp induration, following with subcutaneous tissues atrophy on the right trunk. He was mistaken as panniculitis based on the pathologic findings and treated with topical tacrolimus without any improvement. Immune-related tests were implemented to exclude connective tissues. Imaging examinations such as magnetic resonance was conducted to evaluate the range and degree of the involvement of the skin, soft tissue, and cranial changes. Although no effective treatment to hold back the progress has been reported so far, surgeries might work to restore the appearance to some extent or improve central nerves symptoms if they exist.

Early-onset recurrent panniculitis as a phenotype of NLRC4-associated autoinflammatory syndrome: Characterization of pathogenicity of the p.Ser445Pro NLRC4 variant

Monoallelic NLRC4 gain-of-function variants cause an inflammasomopathy with diverse clinical forms including infantile enterocolitis, recurrent macrophage activation syndrome, cold-induced urticaria-like lesions (or familial-cold autoinflammatory syndrome, FCAS4), and painful subcutaneous nodules. Here, we identified a large family with six consecutive generations affected. Genetic analyses detected the heterozygous p.Ser445Pro NLRC4 variant in three patients, which has been previously reported in a Dutch family with FCAS4. We aimed to describe the clinicopathological features and the functional consequences of the detected NLRC4 variant. Patients presented an early-onset (3 months-6 years) inflammatory disease characterized by recurrent panniculitis, fever and arthralgia. Histopathological examination showed perivascular and interstitial lymphohistiocytic infiltrates in the dermis and mixed panniculitis. Functional analysis supported the conclusion that the p.Ser445Pro NLRC4 variant leads to a constitutive activation of NLRC4-inflammasome and increased plasma levels of IL-18. Prompt recognition of early-onset panniculitis through clinicopathological examination and laboratory biomarkers may allow targeted therapies.

Panniculitis does not predict clinical response in patients with advanced melanoma under targeted therapy

BACKGROUND

BRAF and MEK inhibitors have changed the landscape of treatment for advanced melanoma. Among their side effects, panniculitis has been hypothesized to be associated with better survival.

OBJECTIVES

In this study, we aimed to explore the association between the occurrence of panniculitis during targeted therapy and outcome of metastatic melanoma.

MATERIALS & METHODS

This was a retrospective single-centre comparative study from 2014 to 2019. An English literature review was also conducted to further our understanding of the mechanism(s) involved and identify characteristics of this association, in order to support better management.

RESULTS

Ten patients who developed panniculitis during treatment were matched to 26 controls based on potential confounders at treatment introduction. The prevalence of panniculitis was 5.3%. Median progression-free survival (PFS) for all patients was 8.5 months (range: 3.0-94.0). The median PFS for the group with panniculitis was 10.5 months (7.0-undefined) and 7.0 months (6.0-32.0) for controls (p=0.39). According to the scientific literature, panniculitis occurring during targeted therapy affects mainly young people, predominantly women, with variable delay to onset (with half reported cases occurring in the first month). In addition, panniculitis usually only affects the lower limbs or is associated with other clinical signs (fever, arthralgia), without histological specificity. Discontinuation of targeted therapy is not required as spontaneous remission is usually experienced. Symptomatic treatment may be administered but systemic corticosteroids have not been proven to be effective.

CONCLUSION

In contrast to the belief that there is a link between panniculitis and clinical response to targeted therapy according to the literature, our results show that there is no significant association between the two.

Pancreatitis, panniculitis and polyarthralgia syndrome: A rare complication of pancreatic pathology

Pancreatitis, panniculitis, and polyarthralgia (PPP) syndrome is a rare complication of chronic pancreatitis and occurs due to leakage of pancreatic enzymes in the systemic vasculature. This enzyme leakage leads to multiple manifestations such as polyarthralgia, panniculitis, and bone necrosis due to tissue autodigestion.The inciting pancreatic pathology may be masked, and the presentation may be due to one of the systemic consequences of enzyme leakage, which can present as a diagnostic challenge for clinicians. Here we present a patient who presented with nodular lesions and bone necrosis, and was found to have PPP syndrome. Therefore, a proper understanding of pathophysiology and radiology findings can help with prompt diagnosis and early exploration of management options.

Alpha-1 antitrypsin deficiency: current therapy and emerging targets

INTRODUCTION

Alpha1 antitrypsin deficiency (AATD), a common hereditary disorder affecting mainly lungs, liver and skin has been the focus of some of the most exciting therapeutic approaches in medicine in the past 5 years. In this review, we discuss the therapies presently available for the different manifestations of AATD and new therapies in the pipeline.

AREAS COVERED

We review therapeutic options for the individual lung, liver and skin manifestations of AATD along with approaches which aim to treat all three. Along with this renewed interest in treating AATD come challenges. How is AAT best delivered to the lung? What is the desired level of AAT in the circulation and lungs which therapeutics should aim to provide? Will treating the liver disease increase the potential for lung disease? Are there treatments to target the underlying genetic defect with the potential to prevent all aspects of AATDrelated disease?

EXPERT OPINION

With a relatively small population able to participate in clinical studies, increased awareness and diagnosis of AATD is urgently needed. Better, more sensitive clinical parameters will assist in the generation of acceptable and robust evidence of therapeutic effect for current and emerging treatments.

A Rare Case of Localized Hypertrichosis in Conjunction with Erythema Nodosum

Acquired hypertrichosis can occur in local inflammation. Erythema nodosum (EN) is a hypersensitivity reaction to various underlying antigenic stimuli including Mycobacterium tuberculosis, which causes inflammation in the septa of subcutaneous fat. There were several case reports that describe the association of localized hypertrichosis (LH) with traumatic panniculitis and lupus panniculitis. To our knowledge, this is the first reported case of acquired LH associated with EN. Thus, EN can be added to the list of causes of localized hypertrichosis.

Marked Hypoleptinemia Precedes Overt Fat Loss in Immune Checkpoint Inhibitor-induced Acquired Generalized Lipodystrophy

Immune checkpoint inhibitors (ICIs) targeting cancer cells that evade immune T-cell regulation have revolutionized the treatment of metastatic carcinomas. Unfortunately, secondary endocrinopathies associated with ICI, including adrenal insufficiency, primary hypothyroidism, autoimmune diabetes, and rarely hypoparathyroidism, are increasing. Lipodystrophy, presumably due to the autoimmune destruction of adipocytes, leading to metabolic complications, is a less recognized adverse effect of ICI therapy. We present a case of a 66-year-old Caucasian woman treated with pembrolizumab, an anti-programmed death 1 inhibitor, for metastatic lung adenocarcinoma. Fifteen months after the treatment initiation, she was found to have hyperglycemia, hyperlipidemia, and hepatic steatosis but without any evidence of autoimmune diabetes. She was also noted to have isolated buccal fat pad loss, raising suspicion of acquired lipodystrophy. Despite well-preserved subcutaneous fat over the trunk and limbs, she had undetectable serum leptin levels. Whole-body fluorodeoxyglucose (FDG)-positron emission tomography scan showed diffuse mild FDG activity throughout the subcutaneous tissue, suggesting underlying inflammation. Over the next 3 months, she developed progressive fat loss leading to generalized lipodystrophy. Adipose tissue dysfunction, secondary to ICI-induced subclinical panniculitis, precedes overt fat loss and is characterized by hypoleptinemia and metabolic abnormalities.

[Characteristics of the course of lupus erythematosus panniculitis in a retrospective analysis of 17 patients]

INTRODUCTION

Lupus erythematous panniculitis (LEP) is a rare type of chronic cutaneous lupus erythematous. Clinical characteristics are tender, subcutaneous nodules, erythematous plaques. Disfigurement of face and body might develop which affects the patient's quality of life. LEP can be the first sign of systemic lupus erythematous (SLE).

OBJECTIVE

Our aim was to review the clinicopathological characteristics and the course of LEP through our own patients.

METHODS

We retrospectively analyzed the clinical records of 17 LEP patients at Semmelweis University's Department of Dermatology, Venerology and Dermatooncology between 2000 and 2022.

RESULTS

The male : female ratio was 1 : 16, average age was 37.8 years. Lesion localisations were proximal lower (8/17) and upper extremities (7/17), face (4/17), breast (3/17), chest (2/17), buttocks (2/17), back (1/17) and distal lower extremity (1/17). Lesion morphologies were nodules (11/17), plaques (7/17), lipoatrophy (4/17), ulceration (3/17), calcification (1/17). Discoid changes covered in 6 cases. In 10 cases, systemic symptoms were observed (arthritis (4/17), haematological (5/17), renal (2/17), anti-phospholipid syndrome (2/17). 7 patients fulfilled the EULAR/ACR criteria for SLE. Histology showed mixed type panniculitis in 8, lobular in 3 cases. Average time until diagnosis was 24.3 months. Among all our SLE patients, skin symptoms regressed following systemic immunosuppressive treatment. LEP patients with only skin manifestation were often resistant for the therapy of cutaneous lupus erythematous.

CONCLUSION

The diagnosis of LEP often takes months or years. Wider knowledge of LEP would shorten the time to diagnosis, preventing disfigurement and possible damage of internal organs. Based on our observations, LEP without SLE might be treated with early immunosuppression. Orv Hetil. 2023; 164(5): 172-178.

Mouse model of selective cryolipolysis

BACKGROUND

Cryolipolysis is a noninvasive method of destroying adipocytes using controlled cooling, thereby enabling localized and targeted fat reduction. Due to their greater vulnerability to cold injury, adipocytes are selectively targeted, while other cell types are spared.

OBJECTIVES

This study aims to develop a mouse model of cryolipolysis to offer a reliable and convenient alternative to human models, providing a methodology to validate clinical hypotheses in-depth with relative ease, low cost, and efficiency. This further facilitates comprehensive studies of the molecular mechanisms involved in cryolipolysis.

MATERIALS AND METHODS

Mice (C57BL/6J) were placed under general anesthesia and were treated using our custom, miniaturized cryolipolysis system. A thermoelectric cooling probe was applied to the inguinal (ING) area for either a cold exposure of -10°C, or for a room temperature exposure for 10 minutes. The thickness of the subcutaneous fat of the mice was quantified using an optical coherence tomography (OCT) imaging system before and after the treatment. Histological analyses were performed before and after cryolipolysis at multiple time points.

RESULTS

OCT analysis showed that mice that underwent cold cryolipolysis treatment induced a significantly greater reduction of subcutaneous fat thickness 1 month after treatment than the control mice. The mice that received cold treatment had no skin injuries. The selective damage of adipocytes stimulated cold panniculitis that was characterized histologically by infiltration of immune cells 2 and 3 days after treatment.

CONCLUSION

This study shows that cryolipolysis performed in mice yields reproducible and measurable subcutaneous fat reduction, consistent with previous studies conducted in humans and pigs. Future studies can utilize the model of selective cryolipolysis developed by our group to further elucidate the cellular and molecular mechanisms of fat cell loss and improve clinical outcomes in humans.

Visceral extra-abdominal panniculitis after COVID19

"Retractile mesenteritis" was the first name given to a rare, benign, inflammatory disease that affects the adipose tissue of the intestinal mesentery and less frequently other locations. Now labeled as mesenteric panniculitis, the pathogenic mechanism remains unclear. Several stimuli could be involved, and it is sometimes associated with other conditions such as malignancy or autoimmune diseases. We present a case of mesenteric panniculitis with extensive abdominal and extra-abdominal involvement that developed a few months after SARS-COV2 infection, raising the hypothesis of this virus as a potential trigger for autoinflammatory and autoimmune diseases.

Subcutaneous fat necrosis of the newborn: A retrospective study of 32 infants and care algorithm

OBJECTIVE

To describe the clinical and laboratory outcomes of infants with subcutaneous fat necrosis of the newborn (SCFN) and propose a care algorithm.

METHODS

This single-center, retrospective study of infants diagnosed with SCFN at Ann & Robert H. Lurie Children's Hospital of Chicago from 2009 to 2019.

RESULTS

Of 32 infants who met inclusion criteria, most were born full-term (84%), born via cesarean section (58%), had normal weight for gestational age (69%), and experienced delivery complications (53%). Twenty-nine infants (91%) had calcium drawn, and all had hypercalcemia. Three infants developed clinical symptoms of hypercalcemia, two required hospital admission, two developed nephrocalcinosis, and one developed acute kidney injury. The majority of infants (62%) had a peak ionized calcium between 1.5 and 1.6 mmol/L. No infants with peak ionized calcium less than 1.5 mmol/L developed complications of hypercalcemia. Most patients were diagnosed with hypercalcemia (86%) and demonstrated peak ionized calcium levels (59%) within the first 28 days of life. No patients developed hypercalcemia after 3 months of age.

CONCLUSION

Hypercalcemia occurred in 100% of infants who had laboratory monitoring. We recommend obtaining an initial ionized calcium level when SCFN is suspected, and monitoring for the first 3 months of life if hypercalcemia has not been detected. In patients with asymptomatic hypercalcemia less than 1.5 mmol/L, there appears to be low likelihood of related complications. For symptomatic, markedly elevated (>1.6 mmol/L), or persistently elevated levels (>6 months) we suggest coordinated care with endocrinology or nephrology, consider hospitalization, and urinary system ultrasound.

A Tricky Diagnosis of Poncet's Disease

Erythema nodosum (EN) is a type of panniculitis often benign and self-limited. It may, however, be associated with numerous causes, the most common being infections (namely streptococcal infections), of which tuberculosis (TB) is also one. We report the case of a 43-year-old woman who was referred to our outpatient department with signs of a recurrent EN along with an asymmetrical oligoarthritis of the lower limbs. The investigation excluded all etiological causes of EN, except the interferon gamma release assay (IGRA) which was positive. It was assumed a latent TB infection was the cause of EN. Treatment with isoniazid was started, besides prednisolone and colchicine, with maintained clinical remission. There are just a few cases published about this subject and this intends to emphasize the importance of medical history and of an exhaustive search for a cause, as it may slip away due to the absence of symptoms.

Rapid cytologic diagnosis of subcutaneous fat necrosis of the newborn

Subcutaneous fat necrosis of the newborn is a rare self-limited panniculitis that classically presents within the first few weeks of life. The diagnosis is typically clinical, but some cases require skin biopsy with hematoxylin and eosin stain for confirmation. We report a previously undocumented rapid diagnostic protocol that involves collecting a small amount of exudate from a suppurative lesion, placement onto a slide without fixation, and simply viewing the material under a microscope. This novel and practical method of diagnosis reveals doubly refractile crystals diagnostic of subcutaneous fat necrosis without a biopsy, which may be helpful for rapid diagnosis or use in low resource settings.

A case report of COVID-19-associated erythema nodosum: a classic presentation with a new trigger

BACKGROUND

Over the course of the pandemic, cutaneous manifestations of SARS-CoV-2 infections have been increasingly characterized, yet only a few cases of erythema nodosum (EN) are reported in the literature and international registries.

CASE PRESENTATION

In this report, we describe a case of tender, erythematous nodules that appeared acutely on the distal legs in a 48-year-old female with renal transplant following SARSs-CoV-2 infection complicated by prolonged fevers and pneumonia. The patient was diagnosed with a classic presentation of EN arising from a new and emerging trigger-COVID-19 infection. The cutaneous lesions resolved with conservative management.

CONCLUSIONS

This report highlights the importance of clinician awareness of the potential association of COVID-19 with a classic clinical presentation of EN and underscores that these cases can be managed with the same therapeutic repertoire as EN due to other aetiologies. Of note, use of systemic agents was not employed in this case, as our patient improved with conservative therapy alone.

Sputnik-V vaccine-induced panniculitis as a local reactions

Here, a case of Sputnik‐V vaccine‐induced panniculitis was reported. The patient developed erythema, induration, and local tenderness at the injection site after 13 days of the injection. Ultra‐sonography imaging showed inflammation in subcutaneous layers including fat tissue compatible with panniculitis. She received ibuprofen and warm compress, and all symptoms resolved.

A rare case of suspected lupus erythematous panniculitis as the presenting skin feature of juvenile dermatomyositis: A case report

Juvenile dermatomyositis is a rare autoimmune myopathy of childhood, associated with systemic vasculopathy, primarily affecting the capillaries. Panniculitis is seen histologically in about 10% of patients with dermatomyositis; however, its clinical presentation is rare, with only 30 cases presented in the literature to date. The histopathology overlaps with other inflammatory disease states, and is almost identical to the panniculitis seen in lupus erythematous panniculitis. In the cases with both panniculitis and dermatomyositis, skin and muscle inflammation is usually the first clinical manifestation. We present a case of a 16-year-old female with panniculitis as the initial presenting feature of juvenile dermatomyositis in the context of a prior diagnosis of indeterminate colitis.

Ultrasound analysis for pancreatic panniculitis: A case report

Pancreatic panniculitis (PP) is a necrotizing inflammation of subcutaneous fat that is a rare complication of pancreatic disease appearing in 2% to 3% of all patients. It is more common in the elderly and often affects the extremities. It presents as skin inflammation with pain and erythema nodules. We report a case of acute pancreatitis associated with PP in an old female. She was admitted for vomiting and abdominal pain for 3 days and presented with a 2-week history of erythematous subcutaneous nodules on her legs. Laboratory and ultrasonic findings revealed acute pancreatitis. High frequency ultrasound showed hypoechoic foci in subcutaneous soft tissue layer and adipose layer. Histopathological examination confirmed the diagnosis of PP. Nodules disappeared with the resolution of acute pancreatic inflammation. PP may be the first manifestation of pancreatic disease. Imaging features of this pathology are seldom described and ultrasonic diagnosis experience is worth to be accumulated.

Case Report: Generalised Panniculitis as a Post-COVID-19 Presentation in Aicardi-Goutières Syndrome Treated With Ruxolitinib

Aicardi-Goutières syndrome (AGS) is a rare hereditary early-onset encephalopathy. The syndrome was first described in 1984, and is characterised by upregulation of the type I interferon (IFN) pathway, which is involved in the host immune response against viral infections, including SARS-CoV-2. Whilst defects in type I IFN pathways have been described in association with severe coronavirus disease 2019 (COVID-19), less is known about the outcomes of upregulation. We describe an unusual case of generalised panniculitis as a post-COVID-19 phenomenon in a child with AGS. Our patient was initially managed with systemic steroid therapy, but due to relapse of symptoms on weaning, an alternative therapy was sought. In this case, a novel use of ruxolitinib, a JAK inhibitor, has resulted in lasting remission without complications. We discuss the probable protective role of IFN upregulation following COVID-19 infection in AGS and possible immunological mechanisms driving the panniculitis and therapeutic response in our case.

Clinicopathological Characteristics Related to Etiologies of Erythema Nodosum: A 10-Year Retrospective Study

Background

Erythema nodosum (EN) is the most common panniculitis associated with a wide variety of conditions. Updated studies regarding the clinicopathological manifestations related to etiologies of EN and its prognosis are limited.

Objective

We aimed to explore the clinicopathological features in relation to the etiologies of EN and determine characteristics of disease recurrence and its predictive factors.

Methods

A total of 169 patients with biopsy-proven EN or septal panniculitis from January 2008 to September 2018 were retrospectively reviewed. Patients were classified as either idiopathic or secondary EN. Patients’ general information, clinical manifestations, investigations, and recurrence of EN were recorded. The details on histopathological findings were reviewed by a blinded dermatopathologist.

Results

The mean age at diagnosis of EN was 40.6 ± 17.3 years. The majority of patients (85.2%) were female. Idiopathic EN was found in 62.7% of patients. Tuberculosis (23.8%) and drugs (23.8%) were the leading causes of secondary EN. In univariate logistic regression analysis, lesions on upper extremities (p = 0.018), fever (p = 0.003), clinical lymphadenopathy (p < 0.001) favored secondary EN. Histopathologically, the presence of focal peripheral lobular panniculitis with eosinophils was linked to idiopathic EN (p = 0.03). However, multivariable logistic regression analysis failed to demonstrate factors associated with secondary EN. Recurrence was found in 46.6% of patients with no identifiable predictive factors.

Conclusion

Although no clinical risk factors were associated with the etiology of EN, the histopathological presence of eosinophils in focal peripheral lobular panniculitis suggested idiopathic EN.

Pancreatic carcinoma presented with panniculitis and polyarthritis: A rare case

Extrapancreatic manifestations can complicate pancreatic disorders. Pancreatic panniculitis, characterized by subcutaneous fat necrosis, develops in 0.3%-3% of patients with pancreatic disorders. Occasionally, pancreatic panniculitis and polyarthritis occur in the same patient with pancreatic diseases, a rare symptomatic triad known as pancreatitis, panniculitis, and polyarthritis (PPP) syndrome. PPP syndrome is primarily caused by acute or chronic pancreatitis and pancreatic carcinoma. Almost half of the patients with PPP syndrome do not present with gastrointestinal signs, which may lead to a delayed diagnosis of underlying pancreatic disease. The skin and arthritic symptoms may be mistaken for rheumatic diseases. The histological finding of skin lesions is a valuable clue for diagnosing pancreatic diseases. Due to the high mortality rate when PPP syndrome is associated with pancreatic carcinoma, we highlight that the pancreas should be thoroughly examined if a skin biopsy indicates pancreatic panniculitis.

Erythema Induratum of Bazin Accompanied by Atrophy of the Subcutaneous Fat

Erythema induratum of Bazin (EIB) is a predominantly lobular panniculitis with or without vasculitis due to Mycobacterium tuberculosis (MTB) infection. Atrophic scars may remain after EIB was healed. Rare cases of EIB showing sharp skin depression may mimic deep morphea and lupus profundus. A rare case of EIB was reported in a 35-year-old female with slightly tender erythematous-violaceous nodules and hyperpigmented depressed scars on both lower legs, resulting in asymmetrical lower leg shape. Histopathological examination showed lobular panniculitis without vasculitis and granulomatous inflammation consisted of caseous necrosis, epithelioid cells, and multinucleated giant cells. Polymerase chain reaction (PCR) from skin biopsy revealed deoxyribonucleic acid (DNA) of MTB. Tuberculin skin test (TST) was positive with a 20-mm induration, and nuclear 99mTc-ethambutol scintigraphy was positive for tuberculosis infection in one-third distal portion of the left lower leg. Clinical improvements were shown after 6 months of antituberculosis therapy. EIB must be considered in patient with erythematous-violaceous nodules on lower leg, especially in endemic areas of tuberculosis infection since diagnosis can be difficult and occasionally, deceptive.

Ecthyma Gangrenosum and Panniculitis Secondary to Acute Pseudomonas Myositis Without Bacteremia

Introduction

Ecthyma gangrenosum (EG) is a relatively uncommon cutaneous manifestation of an underlying Pseudomonas aeruginosa infection and is clinically described as necrotic with gangrenous ulcers surrounded by erythematous halos. Cases of EG may occur in the absence of bacteremia and have been increasingly reported in literature. Here we present a patient with features of both EG and panniculitis, despite the lack of underlying bacteremia.

Clinical Findings

A 57-year-old male presented to the emergency department with unrelenting right-sided lower back pain and an "itchy and painful" rash of four to five day duration. The patient had an extensive history of intravenous drug abuse and had been hospitalized multiple times for Pseudomonas bacteremia. Upon examination, there were diffuse, erythematous subcutaneous nodules and several individual necrotic ulcerations on the abdomen, upper and lower extremities, surrounded by erythematous halos. An MRI revealed myositis and edema in the right paraspinal region, and blood cultures were negative for Pseudomonas.

Discussion

EG is typically classified as bacteremic or non-bacteremic in nature, and there are limited reports of panniculitis in the absence of bacteremia. This patient's presentation was unusual for the diffuse presentation of non-bacteremic EG with panniculitis. Due to the patient's past medical history of deep-seeded Pseudomonas infections, bacteria could have been directly inoculated into the skin at various injection sites.

Conclusion

While EG is an uncommon but well-recognized dermatologic feature of Pseudomonas bacteremia, panniculitis is reportedly less commonly and likely underrecognized. Physicians should become aware of the cutaneous manifestations of underlying Pseudomonas infection so appropriate antibiotic therapy can be initiated.

Annular lipoatrophy of the ankle: Four new pediatric cases and a review of the literature

Annular lipoatrophy of the ankle is a rare and unique acquired lipoatrophic panniculitis that mainly affects children. There is no consensus on treatment, and the long-term course is not well known. We present four new pediatric cases that contribute to the understanding of this rare disease.

The spectrum of clinical sequelae associated with alpha-1 antitrypsin deficiency

Alpha-1 antitrypsin (AAT) deficiency (AATD) is an autosomal co-dominant condition that predisposes to the development of lung disease, primarily emphysema. Emphysema results from the breakdown of lung matrix elastin by proteases, including neutrophil elastase, a protease normally inhibited by AAT. AATD also predisposes to liver (cirrhosis) and skin (panniculitis) disease, and to vasculitis. The prevalence of AATD is estimated to be approximately 1 in 3,500 individuals in the United States. However, lack of awareness of AATD among some physicians, misperceptions regarding the absence of effective therapy, and the close overlap in symptoms with asthma and non-AATD chronic obstructive pulmonary disease are thought to contribute to under-recognition of the disease. In patients with AATD, treatment with intravenous AAT augmentation therapy is the only currently available treatment known to slow the progression of emphysema. Moreover, smoking cessation and other lifestyle interventions also help improve outcomes. Early diagnosis and intervention are of key importance due to the irreversible nature of the resultant emphysema. Liver disease is the second leading cause of death among patients with AATD and a minority of patients present with panniculitis or antineutrophil cytoplasmic antibody-associated vasculitis, thought to be directly related to AATD. Though no randomized trial has assessed the effectiveness of augmentation therapy for AATD-associated panniculitis, clinical experience and case series suggest there is a benefit. Other diseases putatively linked to AATD include aneurysmal disease and multiple neurological conditions, although these associations remain speculative in nature.

Painless Panniculitis upon the Treatment of Clinically Amyopathic Dermatomyositis with Anti-MDA5 Antibody

Panniculitis, a rare cutaneous manifestation in patients with dermatomyositis (DM), usually presents as a painful erythematous lesion. We herein report a 32-year-old woman with panniculitis that appeared as an indurated plaque without pain or redness after a 4-month episode of clinically amyopathic DM during treatment with prednisolone and tacrolimus. She experienced no pain; however, the firmness and extent gradually worsened. Based on our findings, including the histopathological results, DM panniculitis was diagnosed. Azathioprine was additionally administered, leading to remission. DM panniculitis can develop as a painless induration during immunosuppressive treatment, and azathioprine may be a useful treatment.

Ultrasound in Sports and Occupational Dermatology

Chronic exposure to trauma, friction, or extreme conditions can generate cutaneous or ungual lesions in sports and certain occupations. Although some of these dermatologic conditions are diagnosed with a naked-eye examination, there are cases in which the provision of the underlying anatomic alterations can be helpful for the diagnosis and management. In comparison with computed tomography or magnetic resonance imaging, ultrasound has the highest axial resolution, which is critical for the observation of anatomic changes in the skin and nail. We review the ultrasound characteristics of frequent cutaneous and ungual lesions related to sports and occupations with a clinical correlation. The ultrasound features in some particular conditions such as "biker's and surfer's panniculitis," "fiddler's neck," piezogenic papules, and lipoatrophy semicircularis, among others, are discussed.

Panniculitis in Children

Panniculitides form a heterogenous group of inflammatory diseases that involve the subcutaneous adipose tissue. These disorders are rare in children and have many aetiologies. As in adults, the panniculitis can be the primary process in a systemic disorder or a secondary process that results from infection, trauma or exposure to medication. Some types of panniculitis are seen more commonly or exclusively in children, and several new entities have been described in recent years. Most types of panniculitis have the same clinical presentation (regardless of the aetiology), with tender, erythematous subcutaneous nodules. Although the patient's age and the lesion site provide information, a histopathological assessment is sometimes required for a definitive diagnosis and classification of the disorder. In children, most panniculitides are lobular. At present, autoimmune inflammatory diseases and primary immunodeficiencies have been better characterised; panniculitis can be the presenting symptom in some of these settings. Unexplained panniculitis in a young child should prompt a detailed screen for monogenic immune disorders because the latter usually manifest themselves early in life. Here, we review forms of panniculitis that occur primarily in children, with a focus on newly described entities.

Chronic myeloid leukemia-leukemia cutis mimicking a neutrophilic panniculitis-like leukemia cutis: Report of a rare case

While drug-induced panniculitis is not uncommon in chronic myeloid leukemia (CML) patients on tyrosine kinase inhibitor therapy, it is rare for CML to initially present as a leukemic panniculitis. We present the case of a 45-year-old male with no relevant prior medical history presenting with 6 months of migratory nodules, 2 months of drenching night sweats, and a 20 pound weight loss. Physical examination showed firm subcutaneous nodules with overlying ecchymoses present on the right lateral thigh and left lower back. Biopsy of a nodule from the right thigh showed a subcutaneous lobular panniculitis involved by a dense infiltrate of neutrophils and granulocyte precursors. Fluorescent in-situ hybridization (FISH) was positive for t(9;22)(q34;q11.2)BCR-ABL1 fusion. A concurrent hemogram revealed a white blood cell count elevation of 600,000 K/μL. Bone marrow biopsy examination showed marked myeloid expansion with an increase in granulocyte precursors and Philadelphia chromosome positivity by FISH, consistent with bone marrow involvement by CML. Herein, we describe this unusual and rare case of CML initially presenting as a neutrophilic panniculitis-like leukemia cutis. Arriving at this challenging diagnosis may be easily missed without clinical and laboratory correlation, which would certainly lead to the patient's not receiving life-saving treatment.

Not Just Uterine Adenocarcinoma-Neoplastic and Non-Neoplastic Masses in Domestic Pet Rabbits (Oryctolagus cuniculus): A Review

With increasing numbers of pet rabbits living out their natural lifespan, rabbit oncology is stepping more and more into the limelight. On the other hand, rabbit tumors are less covered in recent editions of textbooks of veterinary pathology than before. We present 1238 cases with neoplastic and non-neoplastic masses in rabbit tissue, submitted from 2008 to 2019, supplemented by a review of the literature on neoplasms in rabbits. Cutaneous masses comprised 47% of submissions. Trichoblastoma was by far the most common skin neoplasm, and nodular suppurative panniculitis was the second most frequent skin nodule in this series. Epithelial as well as mesenchymal cutaneous neoplasms can be virally induced in rabbits (eg, Shope papilloma, myxomatosis) but were infrequent in the current cases. Mammary neoplasms comprised 21% of submitted masses and 94% of these had histologic features of malignancy. Tumors of the female reproductive tract were responsible for 9% of biopsies and were predominantly uterine adenocarcinoma. Polypoid proliferation of rectal mucosa was the most common lesion in the alimentary tract. A broad spectrum of other neoplasms was described, including sarcomas at vaccination sites and ocular posttraumatic sarcomas, comparable to lesions described in cats.