A 44-year-old man comes to the emergency department due to a diffuse, painful skin rash that began abruptly 2 days ago. He has also had fever and malaise but no cough, shortness of breath, abdominal pain, diarrhea, dysuria, or joint pains. Three years ago, the patient was diagnosed with plaque psoriasis involving the scalp, elbows, and knees. He was treated with a high-potency topical corticosteroid ointment, which has improved his symptoms. He stopped using the ointment a week ago. He also has a history of untreated chronic hepatitis C. The patient is sexually active and uses condoms inconsistently.
Temperature is 38.7 C (101.8 F), blood pressure is 130/70 mm Hg, and pulse is 98/min. There is no scleral icterus or lymphadenopathy. Oropharyngeal mucous membranes are normal. Skin examination reveals erythema and lesions as shown below involving his trunk, neck, and extremities.

Which of the following is the most likely diagnosis?

Question

A 44-year-old man comes to the emergency department due to a diffuse, painful skin rash that began abruptly 2 days ago.  He has also had fever and malaise but no cough, shortness of breath, abdominal pain, diarrhea, dysuria, or joint pains.  Three years ago, the patient was diagnosed with plaque psoriasis involving the scalp, elbows, and knees.  He was treated with a high-potency topical corticosteroid ointment, which has improved his symptoms.  He stopped using the ointment a week ago.  He also has a history of untreated chronic hepatitis C.  The patient is sexually active and uses condoms inconsistently.
Temperature is 38.7 C (101.8 F), blood pressure is 130/70 mm Hg, and pulse is 98/min.  There is no scleral icterus or lymphadenopathy.  Oropharyngeal mucous membranes are normal.  Skin examination reveals erythema and lesions as shown below involving his trunk, neck, and extremities.

Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

This patient's clinical scenario is consistent with acute, generalized pustular psoriasis, a form of psoriasis that typically arises in patients with a history of plaque psoriasis. Risk factors include pregnancy, infection, and withdrawal of systemic or high-potency topical glucocorticoid therapy. Manifestations usually begin with painful, erythematous patches followed rapidly by the appearance of several small sterile pustules, which may become confluent ("lakes of pus"). Localized pustular psoriasis is limited to the palms/soles or digits and is not associated with systemic symptoms; generalized (von Zumbusch variant) pustular psoriasis is widespread and often associated with systemic manifestations (eg, fever, malaise, arthralgias), desquamation, and an increased risk of sepsis. Initial supportive treatment includes hydration, local skin care, and systemic antibiotics if secondary infection is present. Definitive management usually requires long-term systemic retinoids (eg, acitretin) and/or immunosuppressive agents (eg, cyclosporine, methotrexate, infliximab). Recurrent episodes are common. (Choice B) Disseminated gonococcal infection can present as an acute septic monoarthritis or as a triad of dermatitis (usually 2-10 painless pustules on the distal extremities), tenosynovitis, and polyarthralgias. A widespread erythematous rash with numerous pustules would be atypical. (Choice C) Herpes simplex typically presents as clusters of vesicles on an erythematous base. Disseminated herpes simplex (eczema herpeticum) is usually associated with severe immune suppression and may spread to the viscera. This patient who recently went off high-potency topical glucocorticoids for plaque psoriasis and then developed widespread pustular lesions is far more likely to have pustular psoriasis. (Choice D) Staphylococcal skin infections (eg, impetigo, folliculitis, cellulitis) are usually localized, not diffuse. Toxin-mediated staphylococcal disease (toxic shock syndrome) can cause erythroderma and rapid decompensation but is not typically associated with pustular lesions. (Choice E) Stevens-Johnson syndrome (<10% of body surface area) and toxic epidermal necrolysis (>30% of body surface area) are characterized by erythematous or purpuric macules and plaques with subsequent necrosis and sloughing. Mucous membranes are involved in >90% of cases. This patient has pustular lesions and no mucosal lesions. Educational objective: Pustular psoriasis is characterized by erythematous patches followed by the appearance of sterile pustules, which may become confluent. It is typically seen in patients with a history of plaque psoriasis who become pregnant, develop an infection, or are withdrawn from glucocorticoid therapy. Patients with widespread lesions can develop systemic symptoms, desquamation, and sepsis. __________ References: Treatment of pustular psoriasis: from the Medical Board of the National Psoriasis Foundation. (http://www.ncbi.nlm.nih.gov/pubmed/22609220)

A 44-Year-Old Man Comes to the Emergency Department Due to a Diffuse