Polymorphous light eruption in Adult
Alerts and Notices
Synopsis
PMLE is most commonly seen in women with lighter skin phototypes aged 20-30, but it can occur in either sex, all ages, and all ethnicities. Attacks most commonly occur during the spring and early summer months, especially after the first sun exposure of the season, and disappear during the winter.
The etiology of PMLE is not well understood. One theory is that UVR modifies antigens in the skin of PMLE patients to make them immunogenic. There are also data to suggest that PMLE involves a type IV delayed-type hypersensitivity reaction. The action spectrum for PMLE is UVA in most cases, but UVB and both UVA and UVB may also incite the response.
Although the condition frequently recurs, the tendency toward the development of PMLE and the severity of the eruption diminish with repeated sunlight exposure. This phenomenon is termed "hardening." As the summer proceeds, it has been observed that the incidence of new eruptions decreases. Prophylactic phototherapy supports this concept of hardening or tolerance.
Despite the variability of presentations, individual patients tend to experience the same clinical manifestations with each episode.
Codes
ICD10CM:L56.4 – Polymorphous light eruption
SNOMEDCT:
238525001 – Polymorphic light eruption
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
- Systemic lupus erythematosus – Check for circulating antinuclear antibodies (ANA) and other associated lupus antibodies; direct immunofluorescence will be positive; skin lesions can be located on sun-exposed and sun-protected areas (in contrast to PMLE, which is primarily in sun-exposed sites).
- Sunburn
- Solar urticaria – Shorter time to onset of eruption with urticarial plaques lasting 1-2 hours.
- Erythema multiforme – Characteristic target lesions; systemic symptoms are prominent (in contrast to PMLE, where fever, malaise, nausea, and headache are rare).
- Hydroa vacciniforme
- Porphyria cutanea tarda – Will have abnormal porphyrin profile (elevated urine uroporphyrin and stool isocoproporphyrin).
- Erythropoietic protoporphyria – Lesions are very painful, and there is an elevated red blood cell protoporphyrin concentration.
- Photoallergic drug reaction – Investigate for drug history; not seasonally associated and does not improve over time.
- Phototoxic drug reaction
- Airborne contact dermatitis
- Drug-induced pseudoporphyria
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Management Pearls
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Therapy
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References
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Last Reviewed:04/30/2017
Last Updated:06/11/2017
Last Updated:06/11/2017
Patient Information for Polymorphous light eruption in Adult
Overview
Polymorphous light eruption is a reaction seen on the skin of people sensitive to sun exposure. This rash most often consists of multiple pink or red bumps or raised patches, but there may also be blisters or splotches. The rash is often itchy.The reaction develops within minutes to hours after being in the sun. The first exposure to sunlight after winter usually causes the worst rash of the year, and the rash may occur every year at this time.
Most lesions will go away within several days and will not leave a scar.
Who’s At Risk
Polymorphous light eruption is most common in women in their 20s with light skin, but it can affect all sexes, ages, and ethnicities.People sensitive to sunlight may develop this rash when they are first exposed to the sun after the winter, such as visitors to tropical locations.
Signs & Symptoms
This skin rash can look like pinkish-red bumps, blisters, or splotches.Self-Care Guidelines
Prevention is key. Avoid spending time in the sun, especially in the middle of the day. Use a broad-spectrum sunscreen and wear protective clothing when outdoors in the sun.An over-the-counter anti-itch cream with hydrocortisone may help calm the rash. Cold compresses and cool baths may also relieve itching.
When to Seek Medical Care
Most people do not seek medical care for polymorphous light eruption. If the reaction is severe and does not go away after several days, consult your medical provider.Treatments
Your physician or dermatologist may prescribe topical corticosteroid cream.Antihistamines such as Benadryl may reduce itching.
If the reaction is severe, corticosteroid pills (like Prednisone) may be prescribed.
Polymorphous light eruption in Adult