๐ Stepwise Approach to Cutaneous Viral Infections
๐ Key Principles โ Nelson Chapter 708
โข Warts (Verruca): Epidermal HPV infection. Most common in children/adolescents. Common warts (HPV 2,4): fingers, hands, knees. Plantar warts (HPV 1): soles, painful with hyperkeratosis. Flat warts (HPV 3,10): face, arms, Koebnerization. Genital warts (HPV 6,11): condylomata acuminata, sexually transmitted in adolescents.
โข Molluscum Contagiosum: Poxvirus. Pearly, dome-shaped papules with central umbilication. Self-limited (6-9 months). Atopic dermatitis and immunodeficiency cause widespread lesions.
โข Treatment Options: Salicylic acid (keratolytic), cryotherapy (liquid nitrogen), cantharidin (blistering), imiquimod (immune modifier), immunotherapy (intralesional Candida/MMR antigen), topical cidofovir (off-label), pulsed dye laser.
โข Recurrent/disseminated warts: Consider primary immunodeficiency (WHIM, DOCK8, NEMO, STK4, ataxia-telangiectasia, severe combined immunodeficiency).