A report describes a case of a 53-year-old Korean woman who presented with a widespread painful rash in the face, neck, torso, arms and legs, which was treated intermittently with systemic steroids for several months before presentation. She described no relevant medical or dermatologic history and denied taking prescription or over-the-counter medications.

Physical examination revealed the patient as afebrile, but she reported general malaise and chills. Widespread erythematous, annular, scaly plaques that merged into polycyclic plaques studded with nonfollicular-based pustules were seen on the forehead, frontal hairline, neck, chest and abdomen, back, arms and legs.

Histopathologic analysis of the lesion demonstrated abundant subcorneal neutrophilic pustules and spongiform assembly of neutrophils in the spinous layer without many eosinophils.

Given the clinical history, physical examination, histopathology and unremarkable drug history, the patient received the diagnosis of generalized pustular psoriasis (GPP). 

She initially received an acitretin 25 mg/d prescription, but the drug cost prohibited its use. She returned to the clinic 2 days later with a worsening condition and then received a sample of risankizumab 150 mg subcutaneously. Three days later, the majority of the pustules on the upper half of her body dried up, and she began to desquamate from head to toe. The patient developed significant edema of the lower extremities, which demanded furosemide 20 mg/d and ibuprofen 600 mg every 6 hours for symptom relief.

Ten days following the initial dose of risankizumab, the patient improved steadily. Her pustules dried up, and she began showing signs of re-epithelialization. Her edema and pain also notably improved. 

The patient then received two more risankizumab 150 mg doses at weeks 4 and 16. At the follow-up 151 days after the initial dose of risankizumab, the patient showed completely clear skin.

Source: Song EJ. Generalized pustular psoriasis treated with risankizumab. Cutis. 2023;111(2):96-98.