Nonsegmental vitiligo follows Blaschko's lines and embryonic pigmentary segments.

BACKGROUND: Pathogenic mechanism that determines the localization of vitiligo patches and thus a patterned distribution in patients with nonsegmental vitiligo has remained poorly elucidated. A distributional similarity of the vitiligo patches with Blaschko's lines has been documented in patients with segmental vitiligo, both isolated segmental vitiligo and mixed vitiligo but never in cases of nonsegmental vitiligo. METHODS: Distribution of nonsegmental vitiligo patches on face and neck regions was assessed and compared with Blaschko's lines and also with embryonic pigmentary segments on the face. RESULTS: This study has documented distributional similarity of the nonsegmental vitiligo patches on face and neck with Blaschko's lines and the "embryonic pigmentary segments" among 154 (58.6%) cases. Patches around the palpebral and other fissures like periorbital, perinasal, perioral, and periaural were more common. In addition to the vitiligo patches, the spared areas were also found to respect the embryonic segmental outlines and follow the Blaschko's lines. CONCLUSION: Distributional pattern of the individual nonsegmental vitiligo patches along the Blaschko's lines and embryonic pigmentary segments suggests that mosaicism might control the susceptibility to the disease process in a patterned manner. LIMITATION: No genetic testing could be performed to confirm the hypothesis. Evaluation of nonsegmental vitiligo was done only on the face and neck areas.

Forehead plaque: a cutaneous marker of CNS involvement in tuberous sclerosis.

BACKGROUND: Tuberous sclerosis complex (TSC) is a neurocutaneous genodermatosis characterized by hamartoma formation in multiple organs. There are no definite cutaneous markers suggestive of central nervous system (CNS) involvement in TSC. AIMS: To study association of forehead plaque seen in tuberous sclerosis patients and CNS involvement in TSC. METHODS: This is a retrospective study of 15 cases of tuberous sclerosis in varying age groups - from 1.5 to 50 years. All the cases were thoroughly evaluated with detailed history; clinical examination; and relevant investigations like X-rays of chest, skull, hands and feet; ultrasound abdomen and computed tomography of brain. RESULTS: Out of the 15 cases, CNS involvement was seen in 8 cases. Seizures were present in 8 cases (53.33%) and mental retardation was seen in 6 cases (40%). Computerized tomography of brain revealed subependymal nodules (SENs) in eight cases (53.33%). In addition to SENs, subependymal giant cell astrocytomas and cortical tubers were seen in 2 cases each. Out of these 8 cases having CNS involvement, in 7 cases forehead plaque was observed. In 1 case, no forehead plaque was observed (X 2 = 1.07, P < 0.05). CONCLUSION: This study shows that there is a statistically significant relationship between the presence of a forehead plaque and CNS involvement in TSC. Therefore, forehead plaque may be considered as a novel cutaneous marker to know the CNS involvement in TSC at an early stage.