A 22-year-old man with a history of asthma presents with a 2-day history of several small and scaling erythematous papules and plaques on his torso, back, and all four extremities. The patient reports that 3 weeks ago he had an unrelenting sore throat that just recently resolved. The patient has never had this skin condition before and denies a family history of psoriasis or any other dermatologic condition.
Which of the following is the likely diagnosis?
A. Plaque-like psoriasis: Guttate psoriasis. The patient's clinical presentation in this question is consistent with a diagnosis of guttate psoriasis. Guttate psoriasis is the second most common form of psoriasis and accounts for less than 10% of cases. Dermatologic examination reveals numerous small and scaling erythematous papules and plaques on the torso and extremities. This type of psoriasis often follows streptococcal pharyngeal infection, so patients should be asked about a recent sore throat or diagnosis of streptococcal pharyngitis. (A) Plaque-like psoriasis is the most common form of psoriasis (nearly 90%) and is characterized by sharply demarcated erythematous scaling plaques, commonly on the elbows, knees, and scalp. (B, D) Pustular and erythrodermic psoriasis are the most severe forms of psoriasis as they both can compromise the protective functions of the skin (temperature control, fluid maintenance, electrolyte balance). Pustular psoriasis is associated with pus-filled blisters rather than plaques. Erythrodermic psoriasis, unlike the other types of psoriasis, usually affects the entire body and gives the skin a “burned” appearance.