Poxvirus infections

Umbilicated pink, firm waxy papules seen mainly in children

If adult with genital lesions, likely sexual transmission

Larger lesions seen in patients with AIDS

Usually self-limited

Treatment: catharidin, cryosurgery, curettage, imiquimod

Henderson- Patterson molluscum bodies on histology (intracytoplasmic inclusion bodies)

Orf
(Contagious pustular dermatosis) (Ecthyma contagiosum)

One to few papules at contact site with infected goat/sheep, ± fever, lymphadenitis; six clinical stages (in order; maculopapular, targetoid, acute, regenerative, papillomatous, regressive)

Supportive treatment as
self-limited

Mainly in shepherds, veterinarians, goat herders, and butchers

Milker’s nodule
(Pseudocowpox)
(Paravaccinia)

Presents as solitary red-purple nodule on finger with slow growth or with multiple cherry-red nodules at inoculation site

Supportive treatment as
self-limited

Recent contact with infected cows, calves, or viral fomites

Local reaction to site of vaccination (erythema or pruritic papule)

Eczema vaccinatum (in atopic patients): diffuse infection in eczematous skin

Supportive; heals with pitted scarring

Prodrome (backache, fever) after incubation period

Macules/papules initially on face, spreads to trunk and extremities → papules turn to vesicles/pustules with central umbilication

Respiratory and contact isolation, vaccination if early

All lesions same stage of development

Transmission via respiratory droplets

Painful inflamed macule or papule at contact site with infected cow → vesicular, then pustular with tendency to ulcerate → deep-seated black eschar with erythema

Supportive as self-limited; heals with scarring

Eschar with surrounding edema/erythema similar to cutaneous anthrax