Clinical Manifestation and Classification of Japanese Patients With Inherited Keratinizing Disorders

This study retrospectively evaluated 77 cases of inherited keratinizing disorders in Tokyo, classifying them into ichthyoses, palmoplantar keratodermas (PPK), and macular/punctuate-type keratodermas. The ichthyoses group was the largest, with 48 cases, followed by PPK with 21 cases, and macular/punctuate-type keratodermas with 8 cases. The study highlighted a discrepancy between observed percentages and reported incidence, likely due to more visits from patients with severe symptoms. Treatment involved topical moisturizers, vitamin D3 analogues, steroids, antibiotics/antifungals, oral retinoids, and antihistamines. The study concluded that while genetic analysis is crucial for definitive diagnosis, a simplified classification based on clinical features is useful for initial diagnosis and treatment, emphasizing the need for standardized guidelines in Japan.