Warts; molluscum contagiosum; condylomata acuminata — expanded notes
HPV warts: pathogenesis and morphology
Cutaneous warts are benign epidermal proliferations caused by human papillomavirus infection of keratinocytes, often entering through microtrauma. Viral replication is linked to keratinocyte differentiation. Common warts are rough hyperkeratotic papules; plantar warts are endophytic under pressure; plane warts are smooth and flat-topped; periungual lesions may damage nail growth.
Diagnosis and management of warts
Diagnosis is usually clinical. Dermoscopy may show red/black dots representing thrombosed capillaries. Paring may reveal pinpoint bleeding. Differential diagnoses include corns, calluses, seborrhoeic keratoses and squamous neoplasia. Many regress spontaneously. Salicylic acid and cryotherapy are common treatments; repeated treatment may be required. Avoid destructive treatment of atypical lesions without biopsy.
Molluscum contagiosum
Molluscum is a poxvirus infection producing dome-shaped, pearly papules with central umbilication. It is common in children and can be extensive in atopic dermatitis or immunosuppression. Adult genital lesions may be sexually transmitted. Histology shows intracytoplasmic molluscum bodies (Henderson–Patterson bodies). Many cases resolve spontaneously; curettage, cryotherapy or selected topical approaches may be used when treatment is needed.
Anogenital warts
Condylomata acuminata are usually caused by low-oncogenic-risk HPV 6 and 11. Lesions may be papular, filiform or cauliflower-like and occur on genital, perineal or perianal skin and mucosa. Examine for atypical pigmentation, ulceration or induration. Differential diagnosis includes condylomata lata (secondary syphilis), molluscum and normal anatomical variants.
Treatment and counselling
Treatment options include patient-applied imiquimod or podophyllotoxin in appropriate patients and provider-administered cryotherapy, trichloroacetic acid or surgical removal. Podophyllotoxin is contraindicated in pregnancy. Recurrence is common because treatment removes visible lesions but may not eradicate HPV. Offer HPV vaccination according to national recommendations; vaccination is preventive, not curative. Discuss STI screening and partner communication sensitively.