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.

Epidermal Langerhans cells resistance to solar‐simulated radiation in actinic prurigo patients with low minimal erythema dose

“…Most patients in the study were women, as had been described in several publications, and the most frequent skin types were III and IV, similar to reports from Latin America and Asia . A low MED was found in 46.6% of the patients, a finding informed in various studies …”

“…7,9 A low MED was found in 46.6% of the patients, a finding informed in various studies. 7,10,21 In the group of patients with normal MED, we found a statistically significant reduction in the median number of epidermal LCs on the uninvolved buttock skin, 72 hours after two MED SSR, compared with the uninvolved and unirradiated buttock skin. A 45%-100% reduction on epidermal LCs has been observed in the buttock skin of healthy individuals, 72-96 hours following exposure to low doses (2-3 MED) of SSR.…”

Characteristics of actinic prurigo in Scotland: 24 cases seen between 2001 and 2015

“…Our study confirms the female predominance of AP, which contrasts with Asian populations where it occurs more commonly in men, with late‐onset, persistent disease . We highlight the relatively young age of onset for most white patients with AP, consistent with previous observations in white and Amerindian patients with AP .…”

“…However, we also show the potential for the disease to manifest for the first time in adulthood, highlighting the importance of considering this diagnosis in older patients. Other white case series showed a mean age of onset of 14 years . However, our case series highlights an additional difference from AP in Asian populations, where onset in middle age is typical …”

“…Thus, the diagnosis may be challenging. Diagnostic delay was also reported in an Australian study, where mean age of disease onset was 14 years, but mean age at diagnosis was 25 years . This highlights the importance of awareness of this rare condition in order to ensure prompt referral and investigation.…”