A 36-year-old man comes to the office due to a 2-day history of a rash on his lower back. The symptoms began with itching and burning pain, followed by the eruption of small, red papules. He has not had similar symptoms in the past. The patient's medical history is significant for rheumatoid arthritis, which is currently being treated with infliximab. He does not use tobacco, alcohol, or recreational drugs. Vital signs are normal. On physical examination, there is an erythematous rash, as shown in the image below.
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The rest of the skin examination is unremarkable. Which of the following is the best treatment for this patient's condition?
This patient has an erythematous rash suggestive of herpes zoster (shingles), which is caused by reactivation of latent varicella zoster virus infection. The rash typically begins with small papules that can eventually become confluent and evolve into vesicles or bullae, with subsequent crusting in 7-10 days. The rash is usually limited to a single dermatome, but may involve adjacent dermatomes; a few scattered lesions may develop in distant areas. Most patients will have associated neuritic symptoms, including pain, itching, burning, and allodynia, which may precede the onset of a visible rash.
Age and immunocompromised status predispose to shingles. This patient likely developed shingles due to infliximab therapy (tumor necrosis factor-α inhibitor). Treatment with antiviral agents (eg, acyclovir, famciclovir, valacyclovir) decreases the duration of symptoms and the incidence of post-herpetic neuralgia, especially if initiated within 72 hours of the onset of symptoms.
(Choice A) Tinea corporis is characterized by pruritic, annular plaques with a scaly border and central clearing. It is treated with topical antifungals (eg, clotrimazole, terbinafine).
(Choice B) Mupirocin is a topical antibiotic used to treat superficial skin infections such as impetigo, which presents with small vesicles with a yellow exudate and honey-colored crust. It is also used to eradicate methicillin-resistant Staphylococcus aureus colonization from the nares.
(Choice C) Topical 5-fluorouracil is used to treat skin conditions caused by rapid cell division, such as actinic keratoses and superficial basal cell carcinomas. These lesions are typically hyperkeratotic and do not normally occur in a dermatomal distribution.
(Choice D) Topical glucocorticoids are used to treat various inflammatory skin conditions, such as contact dermatitis, which presents with erythematous papules and vesicles but is usually extremely pruritic and is more common on exposed skin.
(Choice E) Guttate psoriasis presents with widely scattered, erythematous, scaly papules and plaques. It typically follows a streptococcal infection but can also occur in patients with rheumatoid arthritis, especially those on tumor necrosis factor-α inhibitors. Treatment options include ultraviolet phototherapy, topical glucocorticoids, and vitamin D analogs.
Educational objective:
Herpes zoster is a painful reactivation of the varicella zoster virus that causes a vesicular rash in a dermatomal distribution. Acyclovir and other antivirals may be used to decrease the duration of disease and the incidence of post-herpetic neuralgia.