Narrowband ultraviolet B phototherapy associated with improvement in Netherton syndrome.

Netherton syndrome (NS) is a rare and severe autosomal recessive ichthyosis. We report the case of a patient with NS treated successfully with narrowband ultraviolet B (NB-UVB) phototherapy after failure of low-dose oral isotretinoin. A 16-year-old girl born to consanguineous parents presented with severe ichthyosis. On examination of her hair, she was found to have trichorrhexis invaginata. Genetic analysis revealed a SPINK5 mutation specific for NS. The patient's cousin had the same mutation. The patient developed Cushing syndrome after long-term application of topical steroids. She was treated with low-dose oral isotretinoin with no benefit. NB-UVB phototherapy was started, which resulted in marked improvement after 2 months. In conclusion, we report a case of NS with failure of low-dose oral isotretinoin, for which NB-UVB phototherapy, through its apoptosis-inducing and immunomodulatory effects, was effective. However, long-term use of UVB is limited by its potential side-effects.