Dermatology Online Journal
- Author(s): Hazan, Carole
- et al.
Department of Dermatology, New York University School of Medicine
Carole Hazan MD
Dermatology Online Journal 11 (4): 18
A 46-year-old man presented with a history of a congenital pigment disorder. On physical examination hypopigmented and depigmented patches were present on the mid-forehead, anterior chest, and extremities. He also had loss of pigment of the medial eyebrows and a white forelock. The patient has a family history of a similar congenital pigment disorder, the pattern of which is indicative of the autosomal dominant disorder piebaldism.
A 46-year-old man presented to the Charles C. Harris Skin and Cancer Pavilion for a complete skin examination. He states that he has a pigment disorder. He denies any suspicious lesions and feels otherwise well without systemic complaints. His maternal grandfather, mother, and sister have a similar pigment disorder.
Physical examination reveals patches of hypopigmentation and depigmentation on the mid-forehead, chest, abdomen, and upper and lower extremities. A white forelock and pigment loss of the medial eyebrows were noted. The white areas were enhanced during examination with a Wood's lamp.
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Piebaldism is an inherited autosomal dominant disorder that is associated with a defect in the migration and differentiation of melanoblasts from the neural crest. Piebaldism results from a mutation in the c-kit proto-oncogene, which is located on chromosome 4q12. The c-kit proto-oncogene encodes for the cell-surface tyrosine-kinase receptor, whose ligand is a stem cell and mast cell growth factor. Several pathologic mutations of the c-kit proto-oncogene have been identified in different patients. Correlation of these mutations with the associated phenotypes has led to the recognition of different classes of mutations that result in a series of piebald phenotypes. It is a rare disorder affecting all races with equal gender distribution [1, 2].
Piebaldism presents at birth with depigmented patches on the mid-forehead, central eyebrows, neck, anterior trunk, mid extremities (in a bilateral distribution sparing the hands), feet, back, shoulders, and hips. Islands of hyperpigmented to normally pigmented patches within and at the borders of hypopigmentation are often seen. In 80-90 percent of patients there is a white forelock. The pigment alterations usually remain stable and are permanent. Rare case reports have found associations with Hirschsprung's disease, mental retardation, deafness, and cerebellar ataxia. Patients generally have a normal life span.
The skin depigmentation in piebaldism is unresponsive to medical treatments and phototherapy . Several surgical techniques have been proposed for the treatment of piebaldism. These procedures are usually poorly suited for the treatment of large, hypopigmented plaques because they can result in scars and require multiple donor sites. It has been reported that autologous, cultured epithelial grafts induce scarless repigmentation of large lesions after disepithelialization of the recipient bed . Repigmentation can be seen within 6-8 months with the skin color resembling that of the normal surrounding skin. Alternative treatment modalities include sunscreen or camouflage using hair dyes or Dermablend.
References1. Winship I, et al. Piebaldism: an autonomous autosomal dominant entity. Clin Genet 1991;39:330
2. Spritz RA. Molecular basis of human piebaldism. J Invest Dermatol 1994;103 (Suppl 5):137S
3. Guerra L, et al. Permanent repigmentation of piebaldism by erbium:YAG laser and autologous cultured epidermis. Br J Dermatol 2004;150:715
4. Kumagai N, Uchikoshi T. Treatment of extensive hypomelanosis with autologous cultured epithelium. Ann Plast Surg 1997;39:68
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