Keratosis Pilaris and its Subtypes: Associations, New Molecular and Pharmacologic Etiologies, and Therapeutic Options

Pruritic Trichostasis Spinulosa: A Rare Variant

Trichostasis spinulosa is a disorder of hair follicles characterized by the retention of vellus telogen club hair, leading to the formation of comedo-like lesions. It usually presents over the face and is frequently asymptomatic. We report a 53-year-old female who presented with multiple itchy, discrete, bluish-black, 2-3 mm comedo-like follicular papules and pustules on her breast and lower abdomen for the past 2 years. In-vivo dermoscopy showed keratotic plugs with a tuft of hair. Extraction dermoscopy yielded a cystic structure filled with keratin and multiple vellus telogen club hairs. Histology showed a cyst lined by squamous epithelium containing abundant laminated keratinous debris and a vellus hair shaft. Truncal or breast involvement, as seen in the present case, is relatively rare, and can be pruritic, causing significant morbidity due to itching and secondary bacterial infections. Dermoscopy, especially ex-vivo extraction dermoscopy, can show diagnostic features and obviate the need for abiopsy.

Keratosis Pilaris-like Eruption during Treatment of Chronic Myeloid Leukemia with Tyrosine Kinase Inhibitors: Literature Review and Report of a Case Related to Imatinib

The advent of tyrosine kinase inhibitors (TKIs) blocking BCR-ABL activity has revolutionized the therapeutic management of patients with chronic myeloid leukemia (CML). Adverse cutaneous reactions (ACRs) are common nonhematologic adverse events associated with the use of BCR-ABL TKIs. A characteristic pattern of eruption resembling keratosis pilaris (KP) has been described in patients treated with these drugs, especially nilotinib and dasatinib. The pathogenesis of this ACR is still unknown. This type of reaction appears to be uncommon with imatinib. Here, we report the case of an elderly patient with an asymptomatic KP-like eruption, which appeared one month after starting treatment with imatinib for CML. The case presentation is accompanied by a review of similar reactions in patients with CML treated with BCR-ABL inhibitors, attempting to make an excursus on the molecular targets of such drugs and possible mechanisms underlying this ACR.

Clinical Characteristics of Lichen Amyloidosis Associated with Atopic Dermatitis: A Single Center, Retrospective Study

BACKGROUND

Lichen amyloidosis is a chronic pruritic skin disorder associated with atopic dermatitis, however, the pathogenetic link between these two conditions remains to be elucidated. Only limited research has been performed on patients diagnosed with both pruritic dermatological conditions.

OBJECTIVE

This study aimed to analyze the clinical features of lichen amyloidosis associated with atopic dermatitis.

METHODS

We conducted a matched case-control study of incident lichen amyloidosis with atopic dermatitis between March 2020 and February 2022. Among the 2,481 patients with atopic dermatitis, 20 patients diagnosed with lichen amyloidosis and atopic dermatitis were included as case patients, and 20 patients diagnosed with atopic dermatitis were enrolled as controls. The controls were matched to cases (1:1) by age and sex. We retrospectively reviewed the medical records of the patients.

RESULTS

The prevalence of lichen amyloidosis associated with atopic dermatitis was approximately 0.8%, with a male:female sex ratio of 2.33:1. The recorded onset of lichen amyloidosis associated with atopic dermatitis was more common in adult patients, with moderate-to-severe atopic dermatitis. Lichen amyloidosis lesions in patients with atopic dermatitis were most commonly found on the extremities, sparing the head and neck region. The presence of lichen amyloidosis had no significant impact on severity of atopic dermatitis.

CONCLUSION

In patients with lichen amyloidosis associated with atopic dermatitis, the clinical manifestations of lesions are similar to those of conventional lichen amyloidosis lesions in terms of morphology and regional distribution. Further research is required to elucidate the link between the pathogenesis of these two pruritic dermatological conditions.

Efficacy and Safety of Long-Pulsed 755-nm Alexandrite Laser for Keratosis Pilaris: A Split-Body Randomized Clinical Trial

Introduction

Keratosis pilaris (KP) is a disfiguring disease and is resistant to treatment. Several treatment methods are available, but the efficacy is limited. This prospective, rater-blinded, split-body comparative study investigated the efficacy and safety of long-pulsed 755-nm alexandrite laser in the treatment of KP.

Methods

Twenty-two patients with KP of bilateral arms were enrolled in this study. All participants were randomized and treated with a long-pulsed 755-nm alexandrite laser on the left or right arm in four sessions held 3 weeks apart. The unified moisturizing lotion was applied on both left and right arms once a day. Physicians’ assessment scores and patients’ self-assessment scores were recorded, and skin imaging changes in dermoscopy, high-frequency ultrasound, and skin biopsy were obtained at baseline and 4 weeks after the fourth treatment.

Results

Of the 21 patients who completed the study, 15 were women and 6 were men. At 4 weeks after the fourth treatment, the laser side showed significantly lower total (2.0 versus 4.5), roughness (1.0 versus 2.0), and redness (1.0 versus 2.0) scores according to physicians’ assessment (all P < 0.05). Furthermore, the laser side showed significantly lower total (2.0 versus 4.0), roughness (1.0 versus 2.0), and redness scores (1.0 versus 2.0) according to the patients’ self-assessment (all P < 0.05). The proportions of patients who achieved dermoscopically and ultrasonographically showed excellent improvements in follicular plugs (57.1% versus 14.3%), perifollicular erythema (52.4% versus 9.5%), perifollicular hyperpigmentation (47.6% versus 14.3%), and the number of epidermal bulges (57.1% versus 19.1%) in the laser side was significantly higher than those who achieved such improvements in the control side (all P < 0.05). Histopathology showed that the follicular plugs and inflammatory cell infiltration were improved at the final visit. Three patients exhibited reversible postinflammatory hyperpigmentation.

Conclusion

Long-pulsed 755-nm alexandrite laser treatment is effective and safe in treating both skin roughness and redness in KP.

Trial Registration Number: ChiCTR2100054489.

Keratosis pilaris and filaggrin loss-of-function mutations in patients with atopic dermatitis - Results of a Finnish cross-sectional study

Keratosis pilaris (KP) associates with epidermal barrier defects in atopic dermatitis (AD) but its role in disease severity and concomitant atopic diseases seems to vary between populations. We performed a cross‐sectional observational study with 502 randomly selected AD patients of a Finnish tertiary health care center. At a single clinical examination, disease severity (Rajka Langeland severity score and EASI), clinical signs and patient history were evaluated and total IgE levels and frequent filaggrin (FLG) loss‐of‐function mutations were investigated. There was no link with disease severity (p = 0.649, 95% CI 0.569–0.654), asthma (p = 0.230, 95% CI 0.206–0.281) or atopic sensitization (p = 0.351, 95% CI 0.309–0.392). Keratosis pilaris was significantly associated with palmar hyperlinearity (p < 0.000, 95% CI 0.000–0.006, OR 4.664, 95% CI 2.072–10.496) and the filaggrin loss‐of‐function mutation 2282del4 (p < 0.000, 95% CI 0.000–0.009, OR 4.917, 95%CI 1.961–12.330). The prevalence of KP in the cohort was generally low and KP seems to be infrequent in Finnish AD patients. This may be explained by the fact that the tested FLG loss‐of‐function mutations are rarer in the Finnish population compared for example, with central Europe or Asia. Mutations in other locations of the FLG gene or other genes of the epidermal barrier may play a more important role.

Dermatological and genetic data in tuberous sclerosis: A prospective single-center study of 38 patients

BACKGROUND

Tuberous sclerosis complex (TSC) is a genetic disorder involving the TSC1 or TSC2 gene. Skin signs are prominent, but dermatological data are scarce. This study aims to describe the cutaneous signs of TSC with the genotype.

METHODS

We studied the dermatological characteristics of 38 patients with TSC at the University Hospital of Montpellier. We collected details of genotypic features.

RESULTS

All the patients presented at least one cutaneous sign. The dermatological examination alone was sufficient to establish a definite diagnosis of TSC based on the diagnostic criteria for 34/38 patients. No association was found between cutaneous signs and the presence of a TSC1 or TSC2 mutation. We noted skin signs that were poorly described in the disease, namely epidermal nevus in 3 patients, vascular malformation in 2 patients, and keratosis pilaris in 9 patients.

DISCUSSION

While several studies demonstrate a more severe neurological phenotype in TSC2 mutated patients, skin expression does not appear to differ according to the mutated gene. Further case reports and molecular genetic studies are needed to determine the link between epidermal nevus, vascular malformations, keratosis pilaris and TSC.

Keratosis pilaris in collagen type VI-related disorders

Keratosis pilaris is a common skin condition associated with a number of syndromes, including collagen type VI-related disorders. Our patient, recently diagnosed with Ullrich congenital muscular dystrophy, presented with severe keratosis pilaris, hypotonia, and velvety skin on the palms and soles. We present this case to highlight the importance of including cutaneous findings, such as keratosis pilaris, to aid in the diagnosis when evaluating patients with syndromic features.

Keratosis pilaris atrophicans faciei: An observational, descriptive, retrospective clinical study

Keratosis pilaris atrophicans faciei (KPAF) is a hereditary follicular disorder, an atrophicans subtype of keratosis pilaris (KP) with a highly elusive diagnosis. Clinically, it presents with follicular, horny papules surrounded by an erythematous halo of the cheeks, forehead, chin and eyebrows, and it is followed by a gradual hair loss on the lateral margins of the eyebrows. The onset is as early as a few months after birth, but it is mainly diagnosed in children and adolescents and it can persist through adulthood. At present, the natural progression of the disease is poorly understood, which makes a correct diagnosis highly unlikely. The aim of the present study was to describe the clinical characteristics of KPAF in patients encountered in daily practice, in order to find common characteristics that may aid in the earlier recognition of the disease. An observational, descriptive, retrospective study was performed on 14 patients diagnosed with KPAF between January 2000 and December 2020. The mean age at diagnosis was 17.04 years and the onset of clinical symptoms appeared at a mean age of 4.85 years. The first clinical symptom was KP involving either the upper or lower limbs, or both. Then, erythema of the face appeared at a mean age of 7.21 years, keratotic papules on the face at a mean age of 8.35 years and, finally, loss of hair on the lateral margins of the eyebrows at a mean age of 14 years. The patients also had concomitant xerosis cutis, multiple mole syndrome, acne, contact dermatitis and Laugier-Hunziker syndrome. Evidence of disease progression, associations, as well as efficacious treatment measures are lacking. An earlier diagnosis potentially allows for a more efficacious, targeted treatment option. Either topical emollients, systemic retinoids or laser therapy may prove effective for each patient individually.

Disseminated and recurrent infundibulofolliculitis in children in Mexico

Disseminated and recurrent infundibulofolliculitis is an uncommon non-infectious skin eruption characterized by recurrent, sometimes pruritic, follicular papules commonly seen on the trunk and proximal extremities. We describe the clinical, dermoscopic, and histopathologic characteristics of disseminated and recurrent infundibulofolliculitis in three young pediatric patients from the tropical regions of Mexico, Guerrero, and Chiapas.

Acne in the first three decades of life: An update of a disorder with profound implications for all decades of life

Acne vulgaris is a chronic, inflammatory, skin condition that involves the pilosebaceous follicles and is influenced by a variety of factors including genetics, androgen-stimulation of sebaceous glands with abnormal keratinization, colonization with Cutibacterium acnes (previously called Propionibacterium acnes), and pathological immune response to inflammation. Acne can occur at all ages and this discussion focuses on the first three decades of life. Conditions that are part of the differential diagnosis and/or are co-morbid with acne vulgaris are also considered. Acne in the first year of life includes neonatal acne (acne neonatorum) that presents in the first four weeks of life and infantile acne that usually presents between 3 and 6 months of the first year of life with a range of 3 to 16 months after birth. Acne rosacea is a chronic, inflammatory, skin condition that is distinct from acne vulgaris, typically presents in adults, and has four main types: erythemato-telangiectatic, papulopustular, phymatous and ocular. Treatment options for acne vulgaris include topical retinoids, topical benzoyl peroxide, antibiotics (topical, oral), oral contraceptive pills, isotretinoin, and others. Management must consider the increasing impact of antibiotic resistance in the 21st century. Psychological impact of acne can be quite severe and treatment of acne includes awareness of the potential emotional toll this disease may bring to the person with acne as well as assiduous attention to known side effects of various anti-acne medications (topical and systemic). Efforts should be directed at preventing acne-caused scars and depigmentation on the skin as well as emotional scars within the person suffering from acne.

Treatment of keratosis pilaris and its variants: a systematic review

INTRODUCTION

Keratosis pilaris (KP) is a common, benign skin condition of follicular hyperkeratosis. Although KP is asymptomatic, the cosmetic appearance of KP can lead to psychosocial distress among patients. New emerging treatments are increasingly being utilized. Yet, there is little to no summative data on the treatments of KP and its subtypes.

OBJECTIVE

To summarize existing literature on treatments for KP and its subtypes.

METHODS

A comprehensive search was performed using Pubmed/MEDLINE, Embase and Web of Science databases. The search identified 1150 non-duplicated articles, and 47 articles were included in the review. The primary outcomes measured were KP treatment type and the degree of improvement following therapy.

FINDINGS

Our findings demonstrate that the most supported form of treatment for KP is laser therapy, particularly the QS:Nd YAG laser. Topical treatments - including Mineral Oil-Hydrophil Petrolat, tacrolimus, azelaic acid, and salicylic acid - are also effective at least for improving the appearance of KP.

CONCLUSION

While the measured treatment outcomes varied among studies, laser therapy appears to be the most effective form of treatment. Use of topicals also improved KP lesions.

Seasonal variability in public searches of keratosis pilaris: How the internet can illuminate a pattern in public interest

In this study, we examine keratosis pilaris search patterns using Google Trends to determine any seasonality. Monthly searches were collected from January 2004 to January 2020 using "keratosis pilaris" as the search term in the Google Trends database. The US search data were compared to monthly temperatures and tested for correlation. Worldwide search interest was also acquired and, along with the US data, a two-model analysis was performed to determine any seasonal patterns. Peaks in search interest closely overlapped with higher temperatures in the United States and showed correlation (.44; P < .0001). The US and worldwide search interest also exhibited seasonality, which was confirmed with a sinusoidal regression being the best-fit model (R² = .867 and .895). These results show higher search volume during warmer months in the United States and a clear cyclical pattern in searches worldwide and in the United States. Examination of these trends could elucidate peaks that health care providers may not have been aware of yielding improved resource allocation and preparedness for larger volume periods. This information in conjunction with clinical data could also shed more light in the future on potential peak seasons of incidence and prevalence.

Innovative 1064-nm Nd:YAG Laser Significantly Improves Keratosis Pilaris, A Randomized, Double-Blind, Sham-Irradiation-Controlled Trial

BACKGROUND AND OBJECTIVE

Keratosis pilaris (KP) is a common follicular disorder for which various topical agents and energy-based devices have been used with some efficacy. To evaluate the efficacy of a novel 1064-nm Nd:YAG laser for the reduction of skin roughness, erythema, and hyperpigmentation in KP subjects.

STUDY DESIGN/MATERIALS AND METHODS

Twenty-three subjects with untreated KP on the upper outer arms participated in a randomized, single-blind fashion. One arm of each subject was divided into upper and lower parts. One part was randomized to be treated with an innovative 1064-nm Nd:YAG laser, while the other part received sham irradiation. Subjects received four consecutive treatments at 4-week intervals. Antera3D was used to measure skin roughness, erythema, and hyperpigmentation at baseline and 4 weeks after the last treatment. Moreover, clinical outcomes were also evaluated by subjects' Global Improvement Score (GIS) and subjects' satisfaction grading scores.

RESULTS

Twenty-three subjects completed the study. There was statistically significant reduction of skin roughness measured by Antera3D compared with control group (P < 0.001). There were statistically significant improvements of skin roughness, erythema, hyperpigmentation, and overall appearances graded by subjects' Global Improvement Score (P < 0.001 all). Subjects' satisfaction scores were graded significantly better in treatment parts (P < 0.001). No adverse events including burning, bulla, erosion, post-inflammatory hyper/hypopigmentation, and scar formation developed in any subjects throughout the study period.

CONCLUSION

This innovative 1064-nm Nd:YAG laser has proved to significantly and safely reduce skin roughness in Thai KP subjects compared with control after four sessions. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Disseminate Recurrent Folliculitis and Hidradenitis Suppurativa Are Associated Conditions: Results From a Retrospective Study of 131 Patients With Down Syndrome and a Cohort of 12,351 Pediatric Controls

Background

Hidradenitis suppurativa (HS) is a chronic, inflammatory, recurrent skin disease of the pilosebaceous unit characterized by protean manifestations. Several studies have found an increased incidence and earlier presentation of this disease in patients carrying trisomy 21. Patients with Down syndrome (DS) have a higher risk of developing a wide range of cutaneous manifestations, including HS and chronic folliculitis. Recently, disseminate recurrent folliculitis (DRF) has been reported as an atypical monosymptomatic feature of HS at its onset.

Objective

To assess the prevalence of HS and DRF by comparing a cohort of patients carrying trisomy 21 vs pediatric controls.

Methods

A retrospective 2-year monocentric clinical study was performed by collecting clinical data of 131 patients with DS, aged 4-36 years, followed at the Dermatology Unit and Down Syndrome Regional Center of Bologna University. Data were matched with those coming from 12,351 pediatric controls.

Results

In DS patients, DRF and HS showed a prevalence of, respectively, 6.8% and 24.4%, while 5.3% of patients presented both diseases. In the control group the prevalence for HS+ and DRF+ was 0.5% and 1.2%, respectively, with a 0.14% of overlap cases. The association between HS and DRF proved to be statistically significant in both groups (P < 0.05). In the DS cohort the mean age of symptoms onset was 15.67 (SD: 2.29) years for HS and 13.11 (SD: 4.93) years for DRF. Buttocks were the most frequently affected body area for DRF followed by the inguinocrural area, while in HS buttocks were less frequently involved than groins and upper thighs.

Conclusions

Because of the later onset of HS, patients with DRF at an early age should be monitored for the possible onset of HS in the apocrine-bearing areas.

Dermatologic Problems Commonly Seen by the Allergist/Immunologist

Allergists/immunologists see a variety of skin disorders, some of which have a known immunologic basis whereas others do not. We review the prevalence, etiology, clinical presentation, and effective and low-cost care of common dermatologic conditions seen in outpatient practices. Conditions discussed include pityriasis alba, seborrheic dermatitis, rosacea, acne, tinea infections, intertrigo, lichen planus, tinea versicolor, lichen simplex chronicus, scabies, pityriasis rosea, keratosis pilaris, and seborrheic keratosis. An understanding of frequently encountered cutaneous diseases and their therapies will help provide immediate access to treatment and improve the experience for both the affected patient and the clinician.