POLYMORPHOUS LIGHT ERUPTION
Polymorphous light eruption (PMLE), sometimes called sun poisoning, is an idiopathic photodermatosis that classically presents as a persistent pruritic rash favoring sun-exposed areas of skin hours to days after prolonged sun exposure. As its name implies, PMLE can present with a variety of morphologies in sun-exposed areas including skin-colored to erythematous papules or plaques, vesicles, and erythema multiforme-like lesions. In patients with darker skin types, PMLE may present as pinpoint papules. The cornerstone of preventative measures for PMLE is rigorous sun protection. Other therapies utilizing the concept of photohardening are useful prophylactically. Asymptomatic patients may forgo treatment entirely and are unlikely to present to a dermatologist. Therapy for symptomatic patients should be based on clinical severity. See Table 90-1.
Table 90-1Polymorphous Light Eruption Treatment Table ||Download (.pdf) Table 90-1 Polymorphous Light Eruption Treatment Table
|MEDICATION NAME ||INDICATION ||MECHANISM OF ACTION ||DOSING ||ADVERSE EFFECTS ||SUGGESTED MONITORING ||LEVEL OF EVIDENCE (REFERENCE) |
|Topical Therapy |
|Broad spectrum sunscreen with sun protective factor of at least 30 ||Prevention ||Photoprotective ||Topically with reapplication every 2-3 h ||Skin irritation ||None ||IB1,2 |
|Calcipitriol cream ||Prevention with pretreatment ||Cutaneous immunosuppression ||Twice daily 7 d prior to photoexposure ||Skin irritation ||None ||IB3 |
|Topical corticosteroids ||Treatment of mild to moderate PMLE ||Anti-inflammatory ||Potent topical corticosteroids once to twice daily to affected areas for 5-7 d; use lower potency for affected areas of face ||Atrophy, striae, acneiform lesions ||None ||IV4 |
|Systemic Therapy |
|Oral corticosteroids ||Treatment of severe PMLE ||Anti-inflammatory ||Prednisolone 25 mg for 4-5 d ||Gastrointestinal disturbance; mood disturbance ||None ||IB5 |
|Polypodium leucotomos ||Prevention ||Photoprotective ||According to body weight: less than or equal to 55 kg, 720 mg every day; 56-70 kg, 960 mg every day; and more than 70 kg, 1200 mg every day ||None reported ||None ||IIB6 |
|Hydroxychloroquine ||Treatment of severe PMLE ||Immunomodulatory ||400 mg daily for the first month and then 200 mg daily thereafter ||GI disturbance || |
Baseline CBC w/diff, CMP, at 3-4 wk and every 3 mo thereafter.
Baseline dilated eye exam and regular eye exams thereafter.
|Cyclosporine ||Treatment of severe PMLE ||Immunosuppressive ||Starting dose of 3.3 mg/kg; dose reduced with clinical improvement ||Elevated blood pressure, hirsutism, gingival hyperplasia, hyperuricemia, hypomagnesemia ||CBC w/diff, CMP, urinalysis, baseline blood pressure, uric acid, magnesium.Repeat laboratories at mo 1, mo 2, and every 3 mo thereafter. Not recommended for longer than 1 y. ||III9 |
|Azathioprine ||Treatment of severe PMLE ||Immunosuppressive ||Initial dose of 0.8 mg/kg/d; increase to 1.2 mg/kg/d after 6 wk ||Gastrointestinal disturbance, fatigue, pancytopenia ||CBC w/diff, CMP, TPMT. Consider repeating CBC w/diff and LFTs every 2 wk for the first 2 mo, then repeating every 3 mo thereafter. ||III10 |
|Procedural Therapy |
|Psoralen plus UVA ||Photoprophylaxis ||Photohardening ||2 to 3 times per week for an average of 5 wk in the early spring ||Exacerbations of PMLE ||None ||IB...|