[Erythema nodosum: etiological changes in the last two decades]

First Case of Erythema Nodosum Associated With Pfizer Vaccine

Vaccine-related erythema nodosum is uncommon, especially after the coronavirus disease 2019 (COVID-19) vaccine. This study presents the first case of the Pfizer vaccine associated with erythema nodosum. A 22-year-old healthy woman presented with a five-day history of several red painful areas with swelling in the lower extremities that started one day after receiving the first dose of Pfizer vaccine. Past medical history, laboratory investigation, and chest radiograph revealed normal results. Erythema nodosum is an immune reaction that manifests as multiple, painful nodules commonly seen on the shin that resolved spontaneously two to eight weeks after the onset. In the absence of laboratory and chest radiograph abnormalities and shortly after receiving the Pfizer vaccine, vaccine-related erythema nodosum is the only possible explanation.

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.

Erythema Nodosum: A Practical Approach and Diagnostic Algorithm

Erythema nodosum is the most common form of panniculitis and is characterized by tender erythematous nodules mainly in the lower limbs on the pretibial area. The exact cause of erythema nodosum is unknown, although it appears to be a hypersensitivity response to a variety of antigenic stimuli. Although the etiology is mostly idiopathic, ruling out an underlying disease is imperative before diagnosing primary erythema nodosum. Erythema nodosum can be the first sign of a systemic disease that is triggered by a large group of processes, such as infections, inflammatory diseases, neoplasia, and/or drugs. The most common identifiable causes are streptococcal infections, primary tuberculosis, sarcoidosis, Behçet disease, inflammatory bowel disease, drugs, and pregnancy. We propose a diagnostic algorithm to optimize the initial work-up, hence initiating prompt and accurate management of the underlying disease. The algorithm includes an initial assessment of core symptoms, diagnostic work-up, differential diagnosis, and recommended therapies. Several treatment options for the erythema nodosum lesions have been previously reported; nevertheless, these options treat the symptoms, but not the triggering cause. Making an accurate diagnosis will allow the physician to treat the underlying cause and determine an optimal therapeutic strategy.

Erythema Nodosum: A Manifestation of Salmonella Infection

Erythema nodosum is a delayed-type hypersensitivity reaction with an unknown trigger in the majority of cases. It is characterized by the development of erythematous tender nodules on the shins. Septal panniculitis without vasculitis is a characteristic histopathological finding. We report the case of a 26-year-old woman who presented with a four-day history of an erythematous swollen left lower limb. She was treated with intravenous clindamycin for suspected cellulitis. However, her symptoms persisted. Punch biopsy revealed findings consistent with erythema nodosum. Two days later, she developed colicky abdominal pain associated with non-bloody diarrhea. Stool culture yielded Salmonella enterica serotype enteritidis. Two days after discharge, she presented again with a right breast abscess for which she underwent incision and drainage along with antibiotic therapy. After discharge, she was symptom-free with complete resolution of the cutaneous lesions. The presented case is unique as it had multiple clinical manifestations of Salmonella infection including erythema nodosum, diarrhea, and presumably a breast abscess. It should be kept in mind that gastrointestinal symptoms are not necessarily the initial presentations of Salmonella infection.

Combined reduced-antigen content tetanus, diphtheria, and acellular pertussis (tdap) vaccine-related erythema nodosum: case report and review of vaccine-associated erythema nodosum

Background

Vaccination programs reduce the morbidity and mortality of diphtheria, pertussis, and tetanus. Erythema nodosum is a reactive erythema that can be associated with infections, drugs, and many conditions. The new onset of erythema nodosum after receiving vaccination is uncommon.

Purpose

Combined reduced-antigen content tetanus, diphtheria, and acellular pertussis (Tdap) vaccine-associated erythema nodosum is described and the reports of vaccine-related erythema nodosum are summarized.

Methods

The clinical features of a 39-year-old woman who developed erythema nodosum after receiving Tdap vaccine are reported. Using the PubMed database, an extensive literature search was performed on erythema nodosum, vaccine, and vaccination.

Results

Tdap, the most commonly used booster vaccine against tetanus, diphtheria, and pertussis, is well tolerated in all age groups. Local injection-site reactions are the most common adverse events, whereas headache, fatigue, gastrointestinal symptoms, and fever are the most frequent systemic events. Erythema nodosum has not previously been reported in patients who have received Tdap vaccine. The patient developed erythema nodosum within 48 h after receiving Tdap vaccine; her symptoms cleared and nearly all skin lesions resolved within 2 weeks after initiating oral treatment with ibuprofen, fexofenadine, and prednisone. Vaccine-associated erythema nodosum has previously been reported following vaccination for cholera, hepatitis B, human papillomavirus, malaria, rabies, small pox, tuberculosis, and typhoid.

Conclusion

Vaccine-associated erythema nodosum is uncommon. Erythema nodosum occurring after Tdap vaccination is a rare, yet potential, adverse effect.