Clinical and histopathological spectrum of delayed adverse cutaneous reactions following COVID-19 vaccination.

BACKGROUND: As more people become vaccinated against the SARS-CoV-2 virus, reports of delayed cutaneous hypersensitivity reactions are beginning to emerge. METHODS: In this IRB-approved retrospective case series, biopsy specimens of potential cutaneous adverse reactions from the Pfizer-BioNTech or Moderna mRNA vaccine were identified and reviewed. Clinical information was obtained through the requisition form, referring clinician, or medical chart review. RESULTS: Twelve cases were included. Histopathological features from two injection-site reactions showed a mixed-cell infiltrate with eosinophils and a spongiotic dermatitis with eosinophils. Three biopsy specimens came from generalized eruptions that showed interface changes consistent with an exanthematous drug reaction. Three biopsy specimens revealed a predominantly spongiotic pattern, consistent with eczematous dermatitis. Small-vessel vascular injury was seen in two specimens, which were diagnosed as urticarial vasculitis and leukocytoclastic vasculitis, respectively. There were two cases of new-onset bullous pemphigoid supported by histopathological examination and direct immunofluorescence studies. Eosinophils were seen in 10 cases. CONCLUSIONS: Dermatopathologists should be aware of potential cutaneous adverse reactions to mRNA-based COVID-19 vaccines. Histopathological patterns include mixed-cell infiltrates, epidermal spongiosis, and interface changes. Eosinophils are a common finding but are not always present. Direct immunofluorescence studies may be helpful for immune-mediated cutaneous presentations such as vasculitis or bullous pemphigoid.

Papillary Dermal Elastolysis Secondary to Combination Nivolumab and Cabiralizumab Therapy: Histiocytes and Dermal Mucin as Clues to the Diagnosis.

ABSTRACT: Papillary dermal elastolysis has been described in the setting of experimental combination nivolumab and cabiralizumab immunotherapy. We report a third patient with distinctive, generalized atrophic macules that developed after a morbilliform eruption during a clinical trial for treatment of metastatic pancreatic adenocarcinoma. Histopathological findings demonstrated diminished elastic fibers in the papillary dermis, associated with a histiocyte-rich infiltrate and increased dermal mucin, features that should clue the dermatopathologist to this condition.

Psoriasis With Eczematous Features: A Retrospective Clinicopathologic Study.

BACKGROUND: Dermatopathologists sometimes encounter patients with features of psoriasis vulgaris and additional changes of eczematous dermatoses. These cases are challenging to diagnose, and the clinical implications are unclear. In the age of targeted therapy, it is important to improve our understanding of these findings so that patients are managed appropriately. OBJECTIVE: To characterize the clinical characteristics, histopathological features, diagnostic workup, successful treatment, and outcomes of patients with overlapping histopathologic features of psoriasis vulgaris and eczema. METHODS: We conducted a retrospective chart review of 20 patients who had received the histopathologic diagnosis of psoriasis vulgaris with eczematous changes noted on skin biopsy. A database that included information about clinical characteristics, comorbidities, histopathological features, diagnostic workup, treatment modalities, and outcomes was created and analyzed. RESULTS: Twenty patients were included in this study, with an average age of 57.3 years. After clinicopathologic correlation, most patients were diagnosed with psoriasis (85%), and the remainder were determined to have an eczematous dermatitis. Thirty-five percent of patients were diagnosed with allergic contact dermatitis, either in combination with psoriasis (6 patients) or alone (1 patient). Topical glucocorticoids were the most common effective therapy used, and systemic therapies were required in nearly half of patients for successful treatment. CONCLUSION: This study offers insights into the clinically and histopathologically challenging diagnosis of psoriasis vulgaris with eczematous changes and offers the diagnostic term "eczematized psoriasis" to describe these patients. The presence of allergic contact dermatitis should be considered in these patients.