Cutaneous amebiasis: diagnostic challenges in a rare genital presentation

Abstract

Cutaneous amebiasis (CA) is a rare, often misdiagnosed manifestation of Entamoeba histolytica infection, typically associated with gastrointestinal disease. Its non-specific presentation mimics malignancies or ulcerative conditions, posing diagnostic challenges, particularly in endemic areas with poor sanitation. A 35-year-old immunocompetent female presented with a two-month history of a non-healing ulcer (4×3 cm) on the labia majora and minora, initially misdiagnosed as genital herpes. Despite treatment with valacyclovir, corticosteroids, and empirical antibiotics (doxycycline, nadifloxacin, and azithromycin), the ulcer persisted. Examination revealed a painful ulcer with undermined margins, necrotic slough, and erythema, without systemic symptoms. Laboratory tests (negative ANA, HIV, and Tzanck smear) ruled out autoimmune and viral causes. Histopathological biopsy confirmed CA, showing E. histolytica trophozoites, hyperplastic squamous epithelium, and chronic inflammation. Oral metronidazole (400 mg thrice daily) and topical metronidazole achieved significant healing within two weeks and complete resolution by one month. The case highlights the diagnostic complexity of cutaneous amoebiasis, as its genital presentation resembles herpes or malignancy. Histopathology was critical for diagnosis, especially without intestinal involvement, suggesting possible nosocomial or hygiene-related transmission. Metronidazole’s efficacy aligns with standard protocols, but CA’s rarity delays recognition. Cutaneous amoebiasis requires heightened clinician awareness to avoid misdiagnosis. Histopathological confirmation and prompt metronidazole therapy ensure excellent outcomes. Enhanced vigilance and public health measures are essential in endemic regions to manage this rare, treatable condition effectively.