Clinico-pathological correlation of linear dermatoses along the lines of Blaschko: An observational study

Several epidemiological studies have described linear dermatoses; however, only few studies have correlated linear dermatoses along Blaschko’s lines with the histopathological findings. The aims of this study were to investigate the clinical patterns of various linear dermatological lesions along Blaschko’s lines and investigate the correlations between these dermatological lesions and their histopathological features. Patients who attended our dermatology out-patient department with linear dermatoses along the Blaschko’s lines were included in the study. Detailed history was obtained, clinical examination was performed, and a final provisional clinical diagnosis was noted. Subsequently, biopsy of the lesions was performed for histopathological examination. Of 62 patients who presented with linear lesions along the Blaschko’s lines, 45 patients underwent biopsy and histopathological examination. Of 45 patients who underwent biopsy, clinico-pathological correlation was observed in 100% of those diagnosed with lichen striatus and linear morphea, 89% of those diagnosed with hypomelanosis of Ito, 80% of those diagnosed with linear epidermal nevus, 75% of those diagnosed with lichen planus, and 67% of those diagnosed with nevus depigmentosus. The importance of correlation of linear lesions with their histopathological features in dermatology cannot be over emphasized. However, 100% correlation may be wishful thinking, and a correlation can help choose the appropriate line of management. Our results highlight this discrepancy and add to the knowledge on linear dermatosis.

Clinical spectrum of MTOR-related hypomelanosis of Ito with neurodevelopmental abnormalities

Purpose Hypomelanosis of Ito (HI) is a skin marker of somatic mosaicism. Mosaic MTOR pathogenic variants have been reported in HI with brain overgrowth. We sought to delineate further the pigmentary skin phenotype and clinical spectrum of neurodevelopmental manifestations of MTOR-related HI. Methods From two cohorts totaling 71 patients with pigmentary mosaicism, we identified 14 patients with Blaschko-linear and one with flag-like pigmentation abnormalities, psychomotor impairment or seizures, and a postzygotic MTOR variant in skin. Patient records, including brain magnetic resonance image (MRI) were reviewed. Immunostaining (n = 3) for melanocyte markers and ultrastructural studies (n = 2) were performed on skin biopsies. Results MTOR variants were present in skin, but absent from blood in half of cases. In a patient (p.[Glu2419Lys] variant), phosphorylation of p70S6K was constitutively increased. In hypopigmented skin of two patients, we found a decrease in stage 4 melanosomes in melanocytes and keratinocytes. Most patients (80%) had macrocephaly or (hemi)megalencephaly on MRI. Conclusion MTOR-related HI is a recognizable neurocutaneous phenotype of patterned dyspigmentation, epilepsy, intellectual deficiency, and brain overgrowth, and a distinct subtype of hypomelanosis related to somatic mosaicism. Hypopigmentation may be due to a defect in melanogenesis, through mTORC1 activation, similar to hypochromic patches in tuberous sclerosis complex.

Hypomelanosis Of Ito: A Rare Disorder With Rarer Presentation-Unilateral Retinal Detachment And Bilateral Glaucoma

Hypomelanosis of Ito, also known as Hypomelanosis of Achromia, Incontenentia pigmenti Achromians, pigmentary dysplasia or mosaicism, is a rare dermatological disease with a prevalence of 1 in 8000-10,000 live births predominantly affecting females. Disease is usually sporadic but familial cases have been reported