Do histopathological features correlate with systemic manifestations in dermatomyositis? Analysis of 42 skin biopsy specimens from 22 patients

• Published in: Journal of cutaneous pathology Vol. 49; no. 5; pp. 442 - 447
• Main Authors: Shakshouk, Hadir, Deschaine, Maria A., Wetter, David A., Drage, Lisa A., Ernste, Floranne C., Gibson, Lawrence E., Lehman, Julia S.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.05.2022; Wiley Subscription Services, Inc
• Subjects: Biopsy; connective tissue disease; Dermatitis; Dermatomyositis; Dermatomyositis - pathology; dermatopathology; Humans; Inflammation; interface; Leukocytes (neutrophilic); Lung diseases; Lung Diseases, Interstitial; Malignancy; Monoclonal antibodies; Mucin; Myopathy; Neoplasms; Patients; Pruritus; Retrospective Studies; Sclerosis; Skin; Statistical analysis; Vascular diseases; Vasculitis; dermatopathology; dermatomyositis; interface; connective tissue disease
• ISSN: 0303-6987; 1600-0560
• DOI: 10.1111/cup.14203

Background Understanding whether specific histopathologic features on skin biopsy are predictive of systemic associations in dermatomyositis (DM) would be useful to guide clinical screening. Methods Through retrospective medical record search, clinical and laboratory findings of patients with DM were documented. Existing skin biopsy slides were re‐reviewed blindly. Results Of all biopsy specimens (n = 42), the most frequent histopathological finding was vacuolar interface dermatitis (95%). Other features included perivascular lymphocytic infiltrate (71%), increased dermal mucin (40%), vessel wall thickening (12%), follicular plugging (9.5%), and dermal sclerosis (7%). Neutrophilic infiltrate was observed in three biopsies from a patient with adalimumab‐associated DM. Vasculitis was not observed. There was no statistically significant difference in the presence of any histopathological feature and that of various systemic manifestations (i.e., myopathy, interstitial lung disease [ILD] and malignancy). However, we observed that dense lichenoid infiltrate rather than pauci‐inflammatory changes correlated with severe itching (p < 0.001). Patients with MDA‐5 antibodies were significantly more likely to have vasculopathy than those without (p = 0.029*). Conclusions No dermatopathologic feature was reliably predictive of myopathy, ILD, or malignancy. This finding implies that, regardless of histopathologic findings, patients should be screened for associated conditions as clinically indicated.