This urticarial rash occured 1 day after a trip to Disneyland in the Spring.

POLYMORPHOUS (POLYMORPHIC) LIGHT ERUPTION

Polymorphous Light Eruption (PMLE) is an idiopathic reaction of the skin to ultraviolet light. The key clinical differential is lupus erythematosus.

The mean age at disease onset in one study was 25.9 years for females and 28.1 years for males
Patients are "allergic to the sun." But reaction is delayed, taking several days to develop.
The arms and legs are more commonly affected as face and neck "harden" to the sun's effects.
PMLE is more common in the summer.
Rule out lupus with ANA and SS-A, SS-B.
Patients may "harden" near the end of summer.
In a long-term followup study (23 years after an initial study) of 94 patients [AD 1998;134;1081], approximately a quarter no longer had symptoms and about half had milder symptoms. There seemed to be a correlation with autoimmune disease in women, but few patients went on to develop lupus.

Clinical

Several hours to days after sun exposure, patients may develop papulovesicular, erythematous, lacy, urticarial, papular or plaque-type lesions. The face and neck are not typically affected as these areas, through regular exposure, harden to the sun's effects. Outbreaks occur in the summer and may affect any photoexposed area. Patients who travel to sun-intense areas for brief vacations may be most severely affected. ANA, SS-A, and SS-B should be obtained to exclude lupus erythematosus. Variants include juvenile spring eruption of the ears and springtime and summer eruption of the elbows.

Treatment

Avoid sun
Broad-Spectrum Sunscreen, e.g. tinted sunscreens use iron oxides along with titanium dioxide or zinc.
Hardening (use NB-UVB like psoriasis, 9-12 doses starting 3-4 weeks before vacation)

Prevention of the disease by sun and visible light protection is the best approach. A broad-spectrum sunscreen applied immediately upon wakening and reapplied several times a day is recommended. Because visible light may aggravate PMLE, physical block sunscreens should be used. For any active disease, a potent topical steroid is usually adequate although systemic steroids may be needed. Antimalarials (e.g., hydroxychloroquine 400 mg/d begun several days before and continued throughout the entire vacation) have been used as a preventative measure, as have gradually increasing doses of narrowband UVB.

Narrowband UVB

NB-UVB may be started 3-4 weeks before vacation, 2-3 per week per protocol, as with psoriasis.

Polypodium Leucotomos

Heliocare (Polypodium leucotomos) is a fern extract supplement for which there is some evidence of benefit in PMLE. This author has had one patient for whom Heliocare was highly effective. Additionally, there is relatively good evidence from multiple studies of benefit for sunburn. The risk of sunburn is decreased and the MED (minimal erythema dose) is increased. The usual dose is 240 mg BID. It can be purchased OTC at various pharmacies and Amazon. See also sunburn.

RegionalDerm

It is not the intention of RegionalDerm.com to provide specific medical advice, diagnosis or treatment. RegionalDerm.com only intends to provide users with information regarding various medical conditions for educational purposes and will not provide specific medical advice. Information on RegionalDerm.com is not intended as a substitute for seeking medical treatment and you should always seek the advice of a qualified healthcare provider for diagnosis and for answers to your individual questions. Information contained on RegionalDerm.com should never cause you to disregard professional medical advice or delay seeking treatment. If you live in the United States and believe you are having a medical emergency call 911 immediately.