The Significance of Scalp Involvement in Pemphigus: A Literature Review

The document is a literature review that highlights the importance of scalp involvement in pemphigus, an autoimmune disease that causes blistering and can lead to alopecia in 16-60% of cases. The review, which analyzed 77 articles from databases like PubMed, Embase, and Web of Science, discusses clinical manifestations, histopathology, immunopathology, trichoscopy, and treatment response of scalp lesions in pemphigus vulgaris and foliaceus. It reports that scalp lesions typically present as erosions and crusted or scaly plaques, and sometimes result in alopecia, with scarring alopecia being less common. The review also notes that the Pemphigus Disease Area Index (PDAI) is used to assess scalp involvement and that there is a correlation between anagen hair loss and disease severity. A study within the review included 32 patients and found that follicular acantholysis occurred in 70.6% of pemphigus vulgaris cases and 80.0% of pemphigus foliaceus cases, with varying depths of acantholysis. Over 80% of patients showed miniaturization of sebaceous glands. Direct immunofluorescence (DIF) of plucked hair had a 91% sensitivity in detecting pemphigus vulgaris, and trichoscopy revealed specific features in pemphigus scalp lesions. The review concludes that the scalp is commonly affected in pemphigus due to the high concentration of pemphigus antigens in hair follicles and acknowledges the need for further study on treatment response in severe scalp involvement.