Linear and whorled nevoid hypermelanosis is a rare skin pigmentation disorder, characterized by linear streaks and whorls of hyperpigmented macules along Blaschko\'s lines. Lesions are commonly restricted to the trunk, neck, and extremities, sparing the face, palms, soles, and mucosae. Associated with this, certain cardiovascular, musculoskeletal, neurological, and developmental anomalies have been reported in the literature. Herein, we present a rare case of linear and whorled nevoid hypermelanosis involving the face, with musculoskeletal, genital, aural, and ocular abnormalities.

Laser is being widely used in treating pigmented lesions nowadays. Linear and whorled nevoid hypermelanosis (LWNH) is a rare pigmentary anomaly, and there are only a handful of cases of successful treatment, all with QS 532- and 755-nm laser. The objective of this study was to examine the clinical outcome of QS 694-nm ruby laser in the treatment of LWNH. We report on a 4-year-old boy presented with asymptomatic macular hyperpigmentation over the entire cheek who underwent 3 treatment sessions with QS 694-nm ruby laser. One month after the last treatment, the patient demonstrated significant improvement to the treatment area. Aside from post-procedural purpura lasting approximately 1 week, the patient experienced no serious adverse effects. No recurrence was observed during the 3-month follow-up. Given the excellent results seen in our patients, we recommended the use of QS 694-nm ruby laser as a safe and effective treatment in patients with LWNH.

Pigmentary mosaicism is a term that describes varied patterns of pigmentation in the skin caused by genetic heterogeneity of the skin cells. In a substantial number of cases, pigmentary mosaicism is observed alongside extracutaneous abnormalities typically involving the central nervous system and the musculoskeletal system. We have compiled information on previous cases of pigmentary mosaicism aiming to optimize the handling of patients with this condition. Our study is based on a database search in PubMed containing papers written in English, published between January 1985 and April 2017. The search yielded 174 relevant and original articles, detailing a total number of 651 patients.
Forty-three percent of the patients exhibited hyperpigmentation, 50% exhibited hypopigmentation, and 7% exhibited a combination of hyperpigmentation and hypopigmentation. Fifty-six percent exhibited extracutaneous manifestations. The presence of extracutaneous manifestations in each subgroup varied: 32% in patients with hyperpigmentation, 73% in patients with hypopigmentation, and 83% in patients with combined hyperpigmentation and hypopigmentation. Cytogenetic analyses were performed in 40% of the patients: peripheral blood lymphocytes were analysed in 48%, skin fibroblasts in 5%, and both analyses were performed in 40%. In the remaining 7% the analysed cell type was not specified. Forty-two percent of the tested patients exhibited an abnormal karyotype; 84% of those presented a mosaic state and 16% presented a non-mosaic structural or numerical abnormality. In patients with extracutaneous manifestations, 43% of the cytogenetically tested patients exhibited an abnormal karyotype. In patients without extracutaneous manifestations, 32% of the cytogenetically tested patients exhibited an abnormal karyotype.
We recommend a uniform parlance when describing the clinical picture of pigmentary mosaicism. Based on the results found in this review, we recommend that patients with pigmentary mosaicism undergo physical examination, highlighting with Wood\'s light, and karyotyping from peripheral blood lymphocytes and skin fibroblasts. It is important that both patients with and without extracutaneous manifestations are tested cytogenetically, as the frequency of abnormal karyotype in the two groups seems comparable. According to the results only a minor part of patients, especially those without extracutaneous manifestations, are tested today reflecting a need for change in clinical practice.

Linear and whorled nevoid hypermelanosis (LWNH) is a rare disorder of pigmentation characterized by hyperpigmented macules in a linear or whorled streaky configuration. Lesions are distributed mainly on the trunk and extremities, sparing the palms, soles, and mucosae. Depigmentation occurring in the pre-existing whorls has not been reported till date. Herein, we report one such rare case of familial LWNH with depigmentation.