The answer is B: steroid acne. Steroid acne is a self-limiting skin condition caused by systemic and topical corticosteroid therapy.1
It is not an uncommon problem, especially in oncologic treatment regimens and organ-transplant patients.1
In most cases, the rash appears within two weeks of the onset of corticosteroid therapy and regresses without scars when the drug is discontinued.1
Typical lesions of steroid acne are 1 to 3 mm dome-shaped papules and papulopustules, which are distributed over the face, upper trunk and upper extremities, and are monomorphic in appearance.1
Histopathology shows folliculitis. The pathogenesis of this condition is still controversial, but most experts believe that folliculitis is a common pathologic feature.1
Disseminated herpes zoster infection can be defined as more than 20 lesions outside the primary dermatomal zoster.2
It is rare in healthy persons but common in immunosuppressed patients, and is sometimes associated with visceral and neurologic involvement.2
Disseminated zoster typically appears four to 11 days after the appearance of primary dermatomal zoster and, rarely, may appear without the preceding segmental zoster.2
Characteristic lesions are multiple discreet vesicles. Histopathology reveals intraepidermal vesicles, acantholysis, multi-nucleated giant cells and ballooning degeneration of infected cells with the formation of intranuclear inclusions.
Acne vulgaris is a common skin condition in adolescents and young adults. It appears commonly not only on the face but also on the shoulders and upper back. The lesions consist of comedones, papules, pustules and, sometimes, cysts, usually with various morphologies present at the same time.
Molluscum contagiosum is a benign disease of the skin that commonly affects children. The characteristic lesions are discrete-but-grouped, pearl- to flesh-colored dome-shaped papules, with central umbilication. They contain white cheesy material. Patients with atopic dermatitis and immunosuppression develop atypical lesions that may become quite large and are resistant to treatment. Histopathology shows hyperplastic epidermis and enlarged epidermal cells containing multiple eosinophilic intracytoplasmic inclusion bodies.
Staphylococcal folliculitis is a localized infection of the hair follicles caused by Staphylococcus aureus. It is common in areas of the skin with hair and areas prone to perspire. Though staphylococcal folliculitis can occur on the back, this type of presentation is unusual.