Kaposi sarcoma — DTM&H MCQ

Correct answer: A — Kaposi sarcoma

E) Kaposi sarcoma is correct. Multiple violaceous oral and cutaneous plaques with leg oedema in a person with HIV and a CD4 count under 100 cells/mm3 is the classic presentation of AIDS-associated Kaposi sarcoma, an AIDS-defining illness caused by HHV-8 that becomes far more common as CD4 falls below 200, and particularly below 100 to 150. The hard palate and lower limb skin are the commonest sites, and the associated oedema results from lymphatic obstruction by tumour infiltration rather than simple venous insufficiency. This combination of violaceous mucocutaneous plaques plus limb oedema at a low CD4 count is highly specific for Kaposi sarcoma in an HIV endemic African setting such as Zambia, and management requires prompt ART initiation with consideration of chemotherapy in advanced or symptomatic disease. Why the other options are wrong: E. Yaws: A treponemal infection causing papillomatous skin lesions and bone changes in children in endemic areas, unrelated to HIV status or CD4 count, and it does not cause violaceous plaques or limb oedema. B. Bacillary angiomatosis: Caused by Bartonella species, producing vascular papules that can mimic Kaposi sarcoma but are typically friable and bleed easily rather than violaceous, and it responds rapidly to macrolide or doxycycline therapy rather than needing ART or chemotherapy. D. Buruli ulcer: A Mycobacterium ulcerans infection causing a painless nodule that progresses to a necrotic ulcer with undermined edges, not multiple plaques, and not linked to immunosuppression. C. Cutaneous leishmaniasis: Presents as one or few crusted ulcerating nodules at a sandfly bite site, not widespread violaceous plaques, and not characteristically associated with HIV-related immunosuppression or limb oedema. Key point: Violaceous mucocutaneous plaques plus limb lymphoedema in advanced HIV (CD4 under 200, especially under 100) is pathognomonic for Kaposi sarcoma until proven otherwise.

Reference: WHO Guidelines on the Management of Advanced HIV Disease and Rapid Initiation of ART, section on Kaposi sarcoma (basis for UK DTM&H and BHIVA-aligned practice), NCBI Bookshelf, 2025: https://www.ncbi.nlm.nih.gov/books/NBK620059/