Life Science Encyclopedia

Photodermatitis, or sometimes called by the nonscientific term sun poisoning, is a reaction of the skin to UV rays of the sun, or photoallergy. It may be caused by a medication that makes the skin more sensitive, a skin product (e.g. sunscreen containing PABA, certain fragrances), autoimmune conditions such as systemic lupus erythematosus (SLE) or a vitamin deficiency. Doctors can determine the presence of the disorder through a photo test.

Causes

Many medications cause sun sensitivity, including:

• psoralens, coal tars, photo-active dyes (eosin, acridine orange)
• musk ambrette, methylcoumarin, lemon oil (may be present in fragrances)
• PABA (found in sunscreens)
• salicylanilide (found in industrial cleaners)
• Hexachlorophene (found in some Rx antibacterial soaps)
• Contact with sap from Giant Hogweed. Common Rue (Ruta graveolins) is another phototoxic plant commonly found in gardens.
• Tetracycline antibiotics
• NSAIDs.
• Fluoroquinolone antibiotic: Sparfloxacin in 2% of cases.

Symptoms

May result in swelling, a burning sensation, a red itchy rash sometimes resembling small blisters, and peeling of the skin. Nausea may also occur.

Prevention

Prevention includes avoiding exposure to the sun:

• Stay inside during the brightest hours of the day, from noon to 3 p.m.
• Cover up: wear long sleeves, pants, and a wide-brimmed hat whenever harsh exposure is probable. Remember that cloud cover does not provide protection from UV rays.^{[citation needed]}
• Avoid chemicals that may trigger a reaction (do not, however, stop taking medication without consulting a doctor).
• Wear sunscreen^[1] at least factor 30 with a high UVA protection level.
• If the symptoms are severe, see a doctor.

Foods and treatment

The following foods or treatment may also help:

• Beta Carotene - found in carrots, not proven to be effective
• Omega-3 fatty acids - found in fish and flax seed
• Protein - will especially help individuals whose malnutrition may be a contributing factor.
• Vitamin B3, C, D, and E
• Green tea - antioxidants
• Calendula
• Aloe - external use

References