Prurigo Pigmentosa: A Multi-Institutional Retrospective Study

This multi-institutional retrospective study examined 30 patients with prurigo pigmentosa (PP) from three academic centers in the U.S. over a 10-year period. The study found that PP predominantly affects White and Asian females, with an average age of 41 years. All patients experienced pruritic erythematous papules and hyperpigmentation, primarily on the back and chest. Notably, 40% of patients were on a ketogenic diet before symptom onset. The study did not find a strong association between PP and autoimmune conditions or common atopic conditions. Higher body mass index was prevalent among patients, a novel finding. Oral antibiotics, particularly doxycycline and minocycline, were effective in achieving complete resolution in treated patients. The study suggests that PP has varied etiologies and that biopsy can help rule out other diagnoses but is not definitive for PP.