COMMENTARY

Repigmentation in Progressive Macular Hypomelanosis

Graeme M. Lipper, MD

Disclosures

May 23, 2012

Narrowband UVB Treatment of Progressive Macular Hypomelanosis

Kim MB, Kim GW, Cho HH, et al
J Am Acad Dermatol. 2012;66:598-605

Study Summary

Progressive macular hypomelanosis (PMH) is a fairly common acquired dyschromia characterized by confluent hypopigmented macules and patches involving the torso and proximal extremities, most commonly presenting in young adults with darker skin phototypes.[1] The pathogenesis of PMH remains unknown, but hypothetical roles of the skin bacterium Propionibacterium acnes and reduced melanin production have been proposed.[2,3] Recently, Chung and colleagues[4] reported marked repigmentation in a Korean patient with PMH who was treated with narrow-band ultraviolet B phototherapy (NB-UVB). Inspired by these results, Kim and colleagues conducted a small pilot trial in which they treated 23 Korean patients (69% women; mean age, 28.3 years) with PMH (mean duration, 42.7 months) using NB-UVB monotherapy. Seventeen of these patients completed at least 6 light treatments (mean number, 20.3; mean cumulative UVB dose, 13,919 mJ/cm2). Clinicians assessed the percentage of repigmentation at multiple timepoints and also followed good responders for recurrence of PMH (mean follow-up, 13.2 ± 8.2 months).

Result highlights are as follows:

  • 56.2% of patients experienced more than 90% repigmentation with excellent color match.

  • 81.3% of patients experienced at least 50% repigmentation.

  • Repigmentation only occurred after a minimum of 4-5 treatments and was easier to achieve for the abdomen vs the back.

  • Excellent responders (> 90% repigmentation) received an average of 20.9 sessions to reach optimal repigmentation.

  • 68.7% of responders showed no signs of relapse during follow-up (13.2 ± 8.2 months).

  • PMH tended to relapse more frequently in patients reporting shorter disease duration.

Viewpoint

PMH is a cosmetically bothersome, notoriously difficult condition to treat. Before making this diagnosis of exclusion, clinicians should first rule out other potential causes of torso hypopigmentation, such as tinea versicolor, pityriasis alba, vitiligo, hypopigmented mycosis fungoides, and leprosy.

Traditional PMH treatments, such as topical and systemic antibiotics, yield limited efficacy.[5] In contrast, NB-UVB showed promising results -- at least in the small cohort outlined above -- with a few important caveats:

  • The trial was limited by a small sample size, homogenous patient population (all Asian skin phototypes), and absence of control patients.

  • Follow-up was relatively short (13.2 ± 8.2 months), raising the possibility that NB-UVB-induced repigmentation may prove transient over time, especially without maintenance therapy.

  • Optimal treatment might require a combination approach using antibiotics and phototherapy.

Abstract

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