PHOTOSENSITIVITY

(Polymorphous Light Eruption; Solar Urticaria)

 Basic information

description

• Photosensitivity is a skin reaction to sunlight. There are several types, including:
  • Polymorphous light eruption (PMLE; sun poisoning) is a common, recurrent, abnormal, delayed reaction.
  • Chemical (drug) photosensitivity occurs from use of certain oral drugs or topical drugs and skin products. This reaction can be an irritant (toxic) or immune.
  • Solar urticaria is a rare reaction that causes hives within a few minutes of exposure to sunlight.

FREQUENT SIGNS & SYMPTOMS

• Red or pink skin rash (called photodermatosis), sometimes with small blisters, in areas exposed to sunlight.
• Rash may itch or burn.
• Large hives with solar urticaria. May also have faintness or nausea.

causes

Symptoms are triggered by exposure to sun (ultraviolet light). It is not known why the body develops this reaction. Sunlight exposure may come through glass (e.g., in an automobile) or thin clothing. Some people react to winter daylight as well. Tanning booths are a source of ultraviolet light. Fluorescent lights affect some.

risk increases with

• Use of drugs, products, or herbs that cause increased sensitivity to ultraviolet light:
  • Common drugs include tetracycline antibiotics, thiazide diuretics, sulfa drugs, nonsteroidal anti-inflammatory drugs, birth control pills, the herb St. John's Wort, and others.
  • Some sunscreens and some cosmetics, including lipstick, perfume, and soaps.
  • Certain plants (either eaten or by skin contact).
• Having certain skin disorders such as porphyria.
• Previous episodes of photosensitivity.
• Systemic lupus erythematosus (an immune disorder).
• Family history of polymorphous light eruption.

PREVENTIVE MEASURES

• Stay out of the sun when possible if you have a history of photosensitivity. The hours of strongest ultraviolet light are 10 AM to 2 PM. Avoid tanning booths.
• Wear dark colored clothing that is tightly woven when in sunlight. Wear a hat with a wide brim.
• Sunscreen may help. Use with care. Some sunscreens cause a reaction in photosensitive persons.
• Avoid the drugs or products known to cause photosensitivity. Not all individuals who use these drugs will have a photosensitive reaction. Also, a reaction will be different in different people. A person may have a one time reaction and not experience it again.

expected outcomes

• PMLE rash usually clears up within 5 to 10 days (if sun is avoided). A person becomes less sensitive with gradual sun exposure over time. This is called hardening.
• If a drug or other product is the problem, symptoms usually stop after it is discontinued or sun is avoided. Complete skin healing may take weeks to months.
• In other photosensitivity cases, symptoms may come and go depending on sun exposure.

possible complications

• Skin may be hyperpigmented (darker).
• Chronic rash (a risk for skin aging or skin cancer).

 diagnosis & treatment

general measures

• Many people with mild symptoms may self-treat.
• See your health care provider if you have concerns about the symptoms or they are severe. A physical exam of the affected skin area will be done. Questions will be asked about your sun exposure, products you use, and drugs that you take. A medical test may be done to check your skin's reaction to ultraviolet light.
• Treatment depends on the cause. Switching to different drugs or skin care products may be recommended.
• For sun protection, see Preventive Measures.
• Apply cool, moist compresses to the affected area.
• Phototherapy (a controlled light exposure) or PUVA (uses a drug and light) may be recommended for some.

medications

• Use oral antihistamines or topical drugs (anti-itch, emollient, mild steroids, or anti-inflammatory) for rash.
• Beta-carotene taken orally helps some people.
• Your health care provider may prescribe oral steroids or other drugs (e.g., antimalarials) for severe cases.

activity

No limits, except for avoiding sun exposure.

diet

No special diet. Drink extra fluids.

 notify our office if

You or a family member has photosensitivity symptoms or symptoms don't improve with treatment.

Special Notes: