Acute Polymorphous Light Eruption

Presented by:

David Elpern MD,

Williamstown, MA, USA

on July 17, 2001

M.R. is a 74-year-old woman who presented with a four day history of a very pruritic eruption on the anterior thighs. This followed an excursion to the beach with her grandchildren. It was the first visit to the beach this year. About 10 years ago, the patient had a similar, but more extensive eruption, while vacationing at Cancun.
She is in good general health, her only medication is an occasional ibuprofen, and she was using sunscreen. At the beach, she was wearing shorts and a t-shirt.

There are discrete and confluent juicy erythematous papules and papulovesicles on the anterior thighs and knees in sun-exposed areas. A few lesions are present on the mid upper chest. The remainder of the cutaneous exam is unremarkable.



Acute Polymorphous Light Eruption

In 1985, along with Morison and Hood, I reported on this entity which we also call "papulovesicular light eruption or PVLE. PVLE is the most common type of PMLE - seen in up to 10% of individuals. It occurs early in the season before a susceptible individuals skin has had time to "harden." It occurs when such a person gets a large dose of ultraviolet light and it is not prevented by sunscreens. Eighty-five percent of the 150 patients we reported from Hawaii from Hawaii were using sunscreens during the putative exposures. Over 90% were tourists to the islands. The reason M.R.'s eruption was limited to the thighs and knees is because her face, arms and lower extremities had been hardened by mid June from outdoor exposures through the Spring, but her thighs and knees had been protected until her recent visit to the beach. Acute PVLE is self-limited. With repeated sun-exposures it gradually disappears. It can be prevented by getting graded and gradual exposures. Tanning booths should help to prevent PVLE if used with care. Treatment is symptomatic. Wet dressings and a potent corticosteroid cream or ointment for a few days along with hydroxizine 10 - 50 mg h.s. are often helpful. For severe cases, or when quick improvement is mandatory, 40 - 60 mg of prednisone in divided doses for 4-5 days will provide relief.

1. Elpern DJ, Morison WL, Hood AF Papulovesicular light eruption. A defined subset of polymorphous light eruption.Arch Dermatol 1985 Oct;121(10):1286-8
A distinctive photodermatitis is seen commonly in tourists visiting Hawaii. Analysis of 150 cases revealed that the eruption is acute in onset following exposure to sunlight, is confined to exposed areas, and mainly affects young to middle-aged white women. The clinical presentation is remarkably uniform, consisting of papules, papulovesicles, or vesicles. These findings are consistent with a diagnosis of polymorphous light eruption (PMLE) and the histologic picture supports this diagnosis. Other clinical variants of PMLE were not seen in our patients, however, which suggests that this condition is more monomorphous than polymorphous. We suggest papulovesicular light eruption as a suitable name for this common and distinctive subset of PMLE
2. Morison WL, Stern RS. Polymorphous light eruption: a common reaction uncommonly recognized. Acta Derm Venereol 1982;62(3):237-40
Polymorphous light eruption (PMLE) is usually considered to be an uncommon complaint, although the prevalence in the general population has not been studied. In a survey of 271 apparently healthy subjects, 10% gave a history consistent with a diagnosis of PMLE. The clinical characteristics in the survey cases of PMLE were similar in most respects to those of patients presenting to a clinic with this disorder. However, there was one notable exception, in that there was a striking difference between the clinic and survey cases in the amount of sunlight required to trigger the eruption. Clinic patients required a mean exposure of 30 min as compared with over 3 h in the survey cases. These findings suggest that PMLE is a common disorder but that many individuals have a high threshold of response to sunlight exposure.

Dr. Elizabeth Rosenthal's Comments (7/18/01):

I think this is rather a common entity but is often less severe than the case presented and often only mentioned after the fact by patients coming in for another problem.

Dr. Foong's Comments (7/18/01):

I recently saw a young lady who presented with a 2 day history of pruritic eruption on the cheeks following prolonged sun exposure at the farm in Cameron Highlands. She had similar episodes of photosensitive skin eruption several months ago. She was investigated for lupus erythematosus but was
negative. The lesions cleared with topical eumovate ointment.

In contrast to western experience, PMLE is quite uncommon here, probably because of chronic exposure to UV. It tends to be more persistent though.

A Patient's Perspective (7/26/01):

Hi, Dr. Elpern.
I e-mailed and spoke with you prior to my trip to Hawaii, requesting any new treatments for PMLE. Thanks so much for all your advice. I told you I would let you know how it worked out...

I was so thrilled to find that I did not get one bit of PMLE, and felt so comfortable for the first time in a tropical climate. Of course, I opt for the shade whenever possible, but in the past that has not even helped.

This was what I did:
Went to a tanning parlor for 2 weeks prior to trip. Went about every other day, starting at 8 minutes, and gradually increasing to 12 minutes. I think this was the most important factor, as you had suggested.

Took 25,000 IU of beta carotene (1 tablet) for 2 weeks prior to trip and during trip.

Applied Biosun sunscreen SPF45 to entire body once a day upon waking or showering. Sometimes re-applied during the day if in the pool or at a beach.

I did bring prednizone and hydroxizine, prescribed by my doctor prior to the trip, but did not need to take it. I did not get any sunburn or even a hint of PMLE. I can't tell you how good it felt, since we were gone for 2 weeks and in the past it has almost ruined my tropical vacations. Thanks so much for your advice!

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