Characteristics of acrodermatitis continua of hallopeau in Korea

Background: Acrodermatitis continua of Hallopeau (ACH) is a rare form of pustular psoriasis that is clinically ! characterized by periungual subungual sterile pustules with paronychia, onychodystrophy, and osteolysis of the distal phalanx of the fingers, toes, and atrophic skin. Objective: To review the clinical and histopathological features, treatment outcomes, and prognosis of patient with ACH. Methods: We identified patients who were clinically or histologically diagnosed with ACH between 2006 to 2015 at the Youido St. Mary's Hospital using hospital charts. Clinical manifestations, aggravating factors, association with ! psoriasis, treatment, and prognosis were retrospectively evaluated. Results: Overall, 16 patients (age range, 9~61 years) were identified, including 13 women. All patients had subungual pustulosis with nail changes including onycholysis (69%), trachyonychia (69%), or yellowish chromonychia (44%). Two patients had additional psoriatic lesions on other body parts. Histopathological results of subungual biopsies performed in 9 patients showed acanthosis, inflammatory cell infiltrates, and pustular formation. Treatment ; included dapsone (69%), nonsteroidal anti-inflammatory drugs (63%), methotrexate (31%), and acitretin (13%). Eight i patients were followed for more than 6 months. Among these, 87.5% required long-term treatment lasting longer ! than 6 months, and poor treatment response of <50% was seen in 62.5% of patients. Conclusion: To our knowledge, this is the first study conducted in Korea to report the characteristics of ACH, including its epidemiology, lesion distribution, nail changes, exacerbation factors, presence of psoriasis, pathological j features, treatment response, and duration. Future research is needed to confirm the effectiveness of treatment and develop treatment guidelines.