PHOTOSENSITIVITY

General Information

DEFINITION--Abnormal sensitivity to sunlight (a reaction may occur after only a few minutes exposure).

BODY PARTS INVOLVED--Skin in areas most exposed to sunlight.

SEX OR AGE MOST AFFECTED--Both sexes; all ages.

SIGNS & SYMPTOMS

• A burning reaction similar to those that follow prolonged sun exposure.
• Red skin rash, sometimes with small blisters.
• Dizziness, nausea, vomiting.

CAUSES--

An interaction between photosentizing substances and sunlight causes the cutaneous (skin) reaction. Photosentizing possibilities include:

• The reaction is often produced when certain substances are combined with ultraviolet light. Among those substances are common drugs, taken orally, including antibiotics, sulfonamides, tolbutamide, chlorpropamide, chlorothiazides, tetracycline, griseofulvin, nalidixic acid, psoralens, nonsteroidal anti-inflammatories, anticancer drugs, estrogens, progestins, chlordiazepoxide, cyclamates, phenothiazines, thiazide diuretics. Chemicals in externally applied substances including perfume and after-shave lotions; coal tar products; soaps containing halogenated bacteriostatic agents; even some sunscreen products (containing PABA, PABA esters, cinnamates, benzophenones) can cause a photosensitive reaction.
• Lupus erythematosus (systemic or discoid).
• Porphyria.

RISK INCREASES WITH

Spring and summer seasons. > Exposure to the sun between 11:00 a.m. and 2:00 p.m.

HOW TO PREVENT

• Stay out of the sun when possible if you have a history of photosensitivity.
• When exposed to the sun, use sunscreen lotions with a sun-protective factor (SPF) of 15 or more; wear protective, light colored clothing (including gloves) and broad-brimmed hat.

What To Expect

DIAGNOSTIC MEASURES--

• Your own observation of symptoms.
• Medical history and physical exam by a doctor.
• Determine any underlying cause such as drugs, cosmetics or a medical disorder. Photopatch testing can be used to identify photoallergic causes.

APPROPRIATE HEALTH CARE

• Self care after diagnosis.
• Doctor's treatment.
• Eliminate the photosensitizing agent (change medications if necessary).

POSSIBLE COMPLICATIONS--Recurrence of the rash and other symptoms when exposed to the sun--even for short periods--especially in spring and summer.

PROBABLE OUTCOME--Curable with elimination of photosensitizing agent. Medications may be required to resolve severe reactions.

How To Treat

GENERAL MEASURES--

• Stay out of the sun during the hours of strongest ultraviolet light (11 a.m. to 2 p.m.).
• If you must go out in the sun, wear protective clothing and the most protective sunscreen preparation available.

MEDICATION--Your doctor may prescribe:

• Corticosteroids for severe reactions (oral or topical).
• Antihistamines for itching symptoms.
• Sunscreens for prevention (ones that block both ultraviolet A and B; without PABA as an ingredient).

ACTIVITY--No restrictions, except to avoid prolonged sun exposure.

DIET--No special diet. Drink extra fluids to prevent dehydration.

Call Your Doctor If

• You have symptoms of photosensitivity.
• New, unexplained symptoms develop. Drugs used in treatment may produce side effects.