Anogenital lumps and bumps
Anogenital lesions can be related to sexually transmitted infections, physiological variants that worry the patient, or dermatological conditions unrelated to infection. The clinical diagnostic approach is based on the colour of the lesion and the skin layer involved (epidermis, dermis, or subcutaneous fat compartment). A strong element of pattern recognition is involved in accurate diagnosis. This can only be learnt with experience, but is essential for determination of appropriate treatment. In this chapter the most common anogenital dermatological diagnoses are discussed using an approach based on the colour of the lesion and the skin layer involved. Many of these infections are asymptomatic, enabling ongoing transmission. Some sexually transmitted infections cause symptoms, especially in the anogenital region, and therefore need to be considered in the differential diagnosis of patients presenting with anogenital lesions.