Adult‐onset actinic prurigo: report of 19 patients from Taiwan

Abstract

EditorActinic prurigo (AP) is a chronic idiopathic photodermatosis displaying multiple intensely itchy, hyperkeratotic firm papules and/or nodules over the sun-exposed areas, usually accompanied by excoriation, crusting and lichenification. Classical AP in Native Americans usually begins in childhood, with disease onset at 4-5 years of age. Hereby, we conducted a retrospective study to collect patients with photo-distributed prurigo nodularis-like lesions between 1991 and 2011 in a dermatological tertiary referral centre in Southern Taiwan. A total of 19 patients were recruited and all of them were older than 21 years with Fitzpatrick's skin type of III or IV (Table 1). Ten of them were outdoor workers, including farmers, fishers, construction workers and gardeners. Photoaggravation of the symptoms and numbers of lesions was reported by eight patients (42.1%). Phototesting was performed in nine patients, whereas one patient had reduced minimal erythema dose (MED) to UVA and five patients to UVB. None of them had cheilitis or conjunctivitis. Personal history of atopy, prior widespread eczema, family history of AP or polymorphous light eruption was unremarkable. Histopathology from 18 patients demonstrated epidermal hyperplasia (15/18, 83.3%) with spongiosis (14/18, 77.8%) and parakeratosis (12/18, 60%), most prominent in the persistent lesions.In addition to intensive sun protection measures, treatment was initiated with combination of systemic and topical medications. Topical steroids combined with oral antihistamines were the mainstay of treatment. Systemic steroids, including oral and intramuscular forms, were given in 13 patients for acute exacerbation. Recalcitrant nodular lesions were treated with intralesional steroid injection or cryotherapy, each in five patients. Oral and topical use of doxepin showed significant relief of pruritus in six and three patients, respectively. A transient suppression of new lesions was observed in two of the four patients treated with narrowband UVB phototherapy. Thalidomide 100 mg/day and hydroxychloroquine 200-400 mg/day, each given in two patients for up to 8 weeks, showed limited improvement. One patient did not benefit from treatment with dapsone 100 mg/day for 10 weeks. In spite of every effort, the course of AP seemed to fluctuate with unsatisfying incomplete remission within a mean follow-up period of 52.4 months (range 14 days-13 years).Our results support the existing data from other Asian countries that the adult-onset AP in Asia develops at an older age onset of around 40 years with overwhelmingly male predominance (Table 2). [1][2][3][4][5][6] The association with cheilitis and conjunctivitis seems lower in Asian patients and was absent in our series.

Prurigo actínico en un centro dermatológico de referencia en Colombia: 108 casos

“…Se ha sugerido que el 17 beta-estradiol tiene un efecto protector contra la inmunosupresión ocasionada por la radiación ultravioleta, por lo que las fotodermatosis como el prurigo actínico y la erupción polimorfa lumínica se presentan con mayor frecuencia en las mujeres 30 . Por el contrario, en los estudios realizados en población asiática, la enfermedad predomina en los hombres (81,8- 94,7 %) 31 - 33 .…”

“…La relación entre la aparición o exacerbación de las lesiones cutáneas con la exposición solar se ha reportado en Escocia en el 75 % de los casos 29 , y fue similar en el presente estudio, así como en Asia (6,66-42,1 %) 31 , 38 y Canadá (92 %) 8 . La mediana del tiempo de aparición de las lesiones después de la exposición solar fue mayor a la reportada en Escocia 29 y Canadá 8 , donde los pacientes presentaban lesiones cutáneas a los 10 minutos o menos, y a los 93 minutos, respectivamente.…”

Photodermatoses in skin of colour

“…Epidemiology Actinic prurigo represents a rare, chronic photodermatosis more commonly observed in those of American Indian or Native Alaskan descent, but it has also been described in Caucasians and Asians. 6,10,11,[38][39][40][41][42][43] AP presents in childhood around ages 4 to 5 years old with a female predominance. Adult onset is possible and more frequently seen in Asians around forty years of age.…”

“…Adult onset is possible and more frequently seen in Asians around forty years of age. 43 Segregation analysis performed from twenty probands from three indigenous communities of Canadian American Indians suggests a dominant form of inheritance with incomplete penetrance. 40 Pathophysiology The pathogenesis of this immune-mediated photodermatosis remains unclear.…”

“…AP presents in childhood around ages 4 to 5 years old with a female predominance. Adult onset is possible and more frequently seen in Asians around forty years of age . Segregation analysis performed from twenty probands from three indigenous communities of Canadian American Indians suggests a dominant form of inheritance with incomplete penetrance …”