13 Cases of Leukoderma Punctata after Narrowband UVB Therapy in Vitiligo Patients / 대한피부과학회지

BACKGROUND: Leukoderma punctata is a peculiar disorder with punctiform, hypopigmented and achromic spots. Histopathologically, a focal reduction of melanocytes and melanin granules are found in the depigmented macule. The phototoxic effect of phototherapy on melanocytes has been suggested as the most likely cause. This occurs mostly after application of systemic or topical psolaren on photochemotherapy. However, a case following narrowband UVB therapy is very rare. OBJECTIVE: The purpose of our study was to investigate the characteristics of leukoderma punctata patients and find the cause of leukoderma punctata. METHODS: We reviewed the medical records of leukoderma punctata patients, and a skin biopsy was taken from punctiform hypopigmented macules. The tissues were stained with hematoxyline and eosin, Fontana-Masson, and dopa-oxidase. RESULTS: The average age of patients was 51 years old. There was no difference between results of male and female patients. Involvement sites of patients were mostly the arms and legs. 76% of patients did not have preceding subjective symptoms. In eight of nine patients, a marked reduction of melanin and melanocytes was noted with both Fontana-Masson staining and dopa-oxidase staining. The average total period of PUVA therapy was 26 months and average total dose of PUVA irradiation was 351.2 J/cm2 in leukoderma punctata patients. Before leukoderma punctata developed, the average total period of narrowband UVB therapy was 6.9 months and average total dose of narrowband UVB was 22.45 J/cm2. The results suggest that leukoderma punctata developed in very small dose of narrowband UVB, although it did not develop with large doses of PUVA. CONCLUSION: Narrowband UVB (311 nm) is the most likely spectrum for development of leukoderma punctata.

A Case of Leukoderma Punctata after Topical PUVA Therapy in Segmental Vitiligo Patient / 대한피부과학회지

Leukoderma punctata is a rare side effect of photochemotherapy such as psoralen with solar ultraviolet light (PUVASOL) or psoralen with ultraviolet A (PUVA), and manifests as numerous discrete punctate, hypopigmented and achromic spots. Histopathologically, a focal reduction of melanocytes and melanin granules are found in the depigmented macules, revealed by S-100 and Fontana-Masson staining. The phototoxic effect of photochemotherapy on melanocytes has been suggested as the most likely cause. This occurs mostly after systemic psoralen on photochemotherapy. However, a case following topical PUVA therapy is very rare. We report a rare case of leukoderma punctata in a 6-year-old female after topical PUVA therapy for segmental vitiligo.