Clinical Challenge: White Forelock of the Frontal Scalp - MPR

Clinical Challenge: White Forelock of the Frontal Scalp

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A patient, aged 41 years, presented with red, scaly spots on her forearms which had been increasing in frequency over the past several months. The patient reported that the lesions were located on areas that lost pigment years ago.

The patient’s family history was significant for vitiligo as well as for a distinctive white forelock of the frontal scalp which affects a grandparent, mother, and her two children.

The patient was diagnosed with piebaldism, a rare autosomal dominant disorder characterized by a congenital white forelock and multiple, symmetrical depigmented macules. Typically, individuals with this disorder will present with depigmentation of hair and skin at birth, which is termed...

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The patient was diagnosed with piebaldism, a rare autosomal dominant disorder characterized by a congenital white forelock and multiple, symmetrical depigmented macules. Typically, individuals with this disorder will present with depigmentation of hair and skin at birth, which is termed poliosis and leukoderma.1,2

A white forelock of hair is noted in about 80-90% of cases and can be present with or without the depigmentation.1,3 White hair can also appear in the eyebrows and eyelashes.1 Depigmented, white patches with islands of pigmentation can appear elsewhere on the face, trunk and extremities.4


Piebaldism is typically not associated with systemic disease; however, cases of piebaldism associated with Hirschprung disease and Neurofibromatosis type 1 have been reported.5,6,7 Piebaldism clinically resembles other dermatologic conditions that involve depigmentation of the hair and skin, such as albinism and vitiligo.

Piebaldism results from mutations that arise in abnormal embryonic development of melanocytes.8 The mutations that cause this disorder are in the KIT proto-oncogene and the SLUG gene. Mutations in these genes result in defects in the transmembrane tyrosine kinase receptors, leading to abnormal proliferation and distribution of melanoblasts and melanocytes during development.2,3

Because of melanocyte loss, sunscreen use is mandatory to prevent occurrence of premalignant lesions such as the actinic keratosis experienced by this patient. Makeup and pigmenting agents may be used to camouflage the affected areas. Dermabrasion and grafting of pigmented skin into the vitiligous areas may induce repigmentation and improve cosmesis.9,10

Megha D. Patel, is a student at the Commonwealth Medical College, Scranton, Pennsylvania.

Stephen Schleicher, MD, is an associate professor of Medicine at the Commonwealth Medical College and an Adjunct Assistant Professor of Dermatology at the University of Pennsylvania Medical College. He practices dermatology in Hazleton, Pennsylvania.

References

  1. Tomas I, Kihiczak GG, Fox MD, Janniger CK, Schwartz RA. The International Society of Dermatology. 2004; 43: 716-719.
  2. Spritz RA. J Invest Dermatol 1994; 103 (Suppl. 5): 137S-140S.
  3. Sarma N, Chakraborty S, Bhanja DC, Bhattachraya SR.Indian Journal of Dermatol, Venereol, Leprol. 2014; 80(2): 163-165.
  4. Syrris P, Malik NM, Murday VA. Am J Med Genet. 2000; 95: 79-81.
  5. Mahakrishnan A, Srinivasan MS.. Arch Dermatol. 1980; 116: 1102.
  6. Angelo C, Cianchini G, Grosso MG, et al. Pediatr Dermatol. 2001; 18: 490-493.
  7. Park S, Kim HJ, Ahn SK. Ann Dermatol. 2014; 26(2): 264-266.
  8. Ezoe K, Holmes SA, Ho L, et al. Am J Hum Genet. Jan 1995;56(1):58-66.
  9. Njoo MD, Nieuweboer-Krobotova L, Westerhof W. Br J Dermatol. 1998; 139: 829-833.
  10. Olsson MJ, Jublin L. Br J Dermatol. 2002; 147: 893-904.