Actinic prurigo: A retrospective analysis of 21 cases referred to an Australian photobiology clinic

Abstract

Actinic prurigo (AP) is a rare acquired idiopathic photodermatosis, reported most often in American Indians, but also in Caucasian and Asian populations. The skin lesions in AP predominantly affect exposed sites but may involve covered areas, and often result in postinflammatory scarring. The diagnosis of AP can be difficult and relies on a combination of history, clinical experience and investigations including phototesting and human leucocyte antigen typing. Twenty-one patients (17 women, four men) diagnosed with AP at the photobiology clinic at St Vincent's Hospital Melbourne were reviewed in this retrospective study. The mean age of patients at presentation to the clinic was 25 years, with the mean age of onset being 14 years. Phototesting was undertaken in 20 patients, with 12 (60%) having reduced and eight (40%) normal minimal erythema doses. Human leucocyte antigen typing indicated 18 patients (85.7%) were DR4 positive, with further subtyping of the DR4 allele establishing that 15 patients (71.4%) were DRB1*0407 positive and that two (9.5%) were DRB1*0401 positive. This condition is often recalcitrant, with treatment options including photoprotection, topical and oral corticosteroids, antimalarials, phototherapy and thalidomide.

Caso para diagnóstico

“…2 However, these chromophores have not been identified. [1][2][3] Ultraviolet A and B rays are involved in the process. 3 The disease was described among NorthAmerican Indians and Central and South America mestizos, with very few reports in the Asian and Caucasian population.…”

“…[1][2][3] Ultraviolet A and B rays are involved in the process. 3 The disease was described among NorthAmerican Indians and Central and South America mestizos, with very few reports in the Asian and Caucasian population. 3 Actinic prurigo is strongly associated with HLA-DR4, particularly the DRB1*0407 subtype.…”

“…3 The disease was described among NorthAmerican Indians and Central and South America mestizos, with very few reports in the Asian and Caucasian population. 3 Actinic prurigo is strongly associated with HLA-DR4, particularly the DRB1*0407 subtype. 3 The electronic search of the Anais Brasileiros de Dermatologia did not yield other reports; a single review article from 1984 was accessed.…”

“…3 Actinic prurigo is strongly associated with HLA-DR4, particularly the DRB1*0407 subtype. 3 The electronic search of the Anais Brasileiros de Dermatologia did not yield other reports; a single review article from 1984 was accessed. 4 Symptoms develop at approximately 10 years of age, affecting mostly women.…”

“…3 Mucosas are frequently affected, especially the lips (30-60%) and conjunctiva (about 30%). 7 The most relevant eye alterations are photophobia, pterygium, pinguecula, enanthema, Trantas' dots, hyaline exudates, and follicles, that is, predominantly conjunctival alterations.…”