Actinic prurigo is a rare chronic sunlight-induced pruritic and excoriated papular or nodular eruption with postinflammatory scarring that disproportionately affects indigenous peoples of North and South America. It typically begins in childhood, usually by age 10 and may remit at puberty. Strong association with HLA-DR4 has been identified. Controlled clinical trials are limited. While photoprotection is first-line, actinic prurigo is unique among photodermatoses in its reponse to thalidomide. See Table 91-1.
Table 91-1Actinic Prurigo Treatment Table ||Download (.pdf) Table 91-1 Actinic Prurigo Treatment Table
|MEDICATION NAME ||INDICATION ||MECHANISM OF ACTION ||DOSING ||ADVERSE EFFECTS ||SUGGESTED MONITORING ||LEVEL OF EVIDENCE (REFERENCE) |
|Topical Therapy |
|Broad-spectrum sunscreen (mineral sunscreen for UVA and UVB coverage, SPF >30) and sun avoidance ||First-line ||Sun protection ||Regular application daily ||None ||None ||III1-3 |
|High-potency topical corticosteroids ||Acute episodes ||Anti-inflammatory ||Intermittent short course, up to 14 d ||Atrophy, pigment change, telangiectasias, striae formation, acneiform eruption ||None ||III1-6 |
|Calcineurin inhibitor ||Acute episodes ||Anti-inflammatory ||Up to twice a day ||Skin irritation ||None ||III5 |
|Systemic Therapy |
|Oral antihistamine (eg, hydroxyzine, cetirizine) ||Acute episodes ||Reduce pruritus ||Hydroxyzine (12.5-25 mg po TID prn itch in adults); cetirizine 10 mg daily ||Dizziness, sedation, anticholinergic symptoms, GI upset ||None ||III3,5,6 |
|Oral corticosteroids ||Episoidic exacerbations ||Anti-inflammatory ||Start with 0.5 mg/kg prednisone daily, then taper down ||Immunosuppression, hyperglycemia, HPA axis suppression, osteoporosis ||Blood pressure, glucose, triglyceride, electrolytes every 1-2 mo (may decrease frequency over time) ||III6 |
|Thalidomide ||Severe, persistent disease ||Anti-inflammatory ||Usually start at 100 mg daily for adults and decrease to 50 mg daily for maintenance, treatment duration 1-3 mo; lower doses for children ||Teratogenicity, drowsiness, headache, constipation, weight gain, peripheral neuropathy, increased risk of thromboembolism, leukopenia, thrombocytopenia ||Liver and thyroid function (monthly), complete blood count (monthly), pregnancy testing (weekly during the first month, then monthly) ||III5-8 |
|Cyclosporine ||Refractory disease ||Suppression of T-cell proliferation and activity ||2.5 mg/kg/d ||Nephrotoxicity, hepatotoxicity, hirsutism, hypertension ||Renal and liver function, fasting lipid, blood pressure, electrolytes including magnesium and uric acid (every 2 wk for the first 2 mo, then monthly) ||III9 |
|Procedural Therapy |
|Narrowband UVB ||Refractory disease ||Decrease cell proliferation, immunosuppression, desensitization ||3x/wk, starting in early spring; doses depend on skin type; start with 50% MED and increase 10%-15% per session as tolerated; treatment duration approximately 5 wk ||Erythema, pruritus, provocation of the eruption ||None ||III6,10-12 |
|Psoralen and UVA ||Refractory disease ||Increase in pigmentation and epidermal thickness; suppression of immune response ||2x/wk ||Erythema, photoaging, increased risk of skin cancer, nausea ||Annual skin examination ||III6,13 |
Levels of evidence are based on the Journal of the American Academy of Dermatology guidelines: level IA evidence includes evidence from meta-analysis of randomized controlled trials; level IB evidence includes evidence from ≥1 randomized controlled trial; level IIA evidence includes evidence from ≥1 controlled study without randomization; level IIB ...