Amoebiasis cutis: clinical suspicion is the key to early diagnosis

Amoebiasis cutis is a rare manifestation of Entamoeba histolytica, primarily an intestinal pathogen, which occurs as a complication of amoebic dysentery. Primary cutaneous amoebiasis occurs from contamination of pre-existing wounds. A high degree of clinical suspicion and demonstration of trophozoites from lesions are important for making an early diagnosis lest these patients should suffer significant morbidity. A HIV-negative and otherwise healthy 40-year-old man presented with a well-defined, indurated, painful, progressively enlarging plaque with overlying ulcers and pus discharging sinuses involving buttocks, perianal/perineal area and part of the left thigh of 3 years' duration. A wide array of investigations was unhelpful but demonstration of Entamoeba histolytica trophozoites in wet-drop preparation from the ulcer margin was diagnostic. The trophozoites were also visualized both in H&E and periodic acid Schiff-stained histological sections. Resolution of lesion was observed 2 weeks after treatment with oral metronidazole 800 mg three times a day and wound care.