Anal involvement in patient with pemphigus vulgaris: Case report.

[INTRODUCTION AND IMPORTANCE] Pemphigus Vulgaris (PV) is a low incidence autoimmune mucocutaneous bullous disease, in which pathogenic antibodies are directed against the keratinocyte cell surface. Although anal involvement is unusual, correlations between its appearance and disease severity have been recently reported.

[CASE PRESENTATION] A 42-year-old male presented with an anal fissure and a year of recurrent oral and pharyngeal aphtha. A chemical sphincterotomy with botulinum toxin plus fissurectomy was performed. 3 years later an upper eyelid injury raised suspicion of pemphigus vulgaris (PV), tested negative for specific antibodies. A couple years later, an anal fissure, and suspected Crohn's disease, led to a second intervention. Surgical analysis unveiled characteristics indicative of a vegetating variant of PV.

[CLINICAL DISCUSSION] Anal involvement in PV varies in prevalence, with studies reporting rates between 2 % and 27.98 %. This manifestation often accompanies late disease stages and may indicate severity, notably in association with oral lesions. Patients might not readily discuss anal symptoms, leading to potential underreporting. Anal PV is linked to other lesions (ocular, nasal, genital) and the severity of oral PV. Even when other sites are in remission, anal recurrence can occur. Early recognition and follow-up are crucial, highlighting the need for routine anal examination and confirmatory diagnostics.

[CONCLUSION] PV lesions can present on the skin or mucosa, although oral lesions are the most common site of initial presentation. Anal PV is a diagnostic challenge, and this case illustrates the importance of a careful evaluation.