Photodermatitis

Photodermatitis is a skin condition caused by adverse reaction of immune system to contact with ultraviolet rays of sunlight. Scaling, skin rash, and blistering may be experienced by patients. The symptoms and its intensity differ from one affected person to another and the condition can be acute or prolonged.

Photodermatitis is caused by a variety of factors such as hereditary reasons, adverse response to some plants, drug side effects, etc. It is however a mild skin disorder and can be corrected with drugs, home remedies, and self-care.

Symptoms of photodermatitis

Photodermatitis patients may suffer from below listed signs and symptoms:

Skin which is exposed to UV rays may experience adverse outbreaks
Itchy elevated blotches, bumps, or blisters may form
The anomalous rashes and patches on skin cause chronic itchiness
Skin discoloration or darkening may occur in patches
Photodermatitis lesions may appear like eczema rashes
There may be dry and scaly abnormal areas on skin
In chronic cases, the skin may become thick and elicit scarring
Hives may also form
Skin with photodermatitis blisters/rashes may elicit burning sensations
Fever and chills, headache, nausea
Pain, redness, swelling, and inflammation of affected skin areas
If photodermatitis occurs due to genetic causes, then affected people may be more susceptible to developing skin cancer

Causes of photodermatitis

Some of the common causes of photodermatitis are mentioned below

Underlying conditions

Photosensitive reactions of skin may occur due to hereditary or metabolic triggers/factors, like pre-existing genetic conditions such as pellagra which is caused due to niacin and B3 vitamin deficits.
Lupus, eczema, and other skin disorders can make the skin more photosensitive and trigger occurrence of photodermatitis.
Conditions like polymorphic light eruptions, which are characterized by sensitivity to UV rays of sun, may also trigger photodermatitis

Direct effect/Allergic reaction to chemicals and medicines

Some types of chemicals and medicines can react to sunlight exposure and cause sunburn, hives, and eczema-like skin rashes. These reactions may occur due to direct contact with toxins released by substances, or it can occur as part of an allergic reaction.
- Direct poisonous effect may be observed after using medicines like antibiotics (sulfonamides or tetracycline); antifungals (griseofulvin, etc.); psoralens and coal tar derivatives used for psoriasis topical therapy; chemotherapy drugs/agents; retinoids (tretinoin) and acne medicines containing retinoic acid; NSAIDs; antimalarial medicines (quinine, etc.); diuretics; oral medicines for diabetes containing sulfonylureas; antidepressants (tricyclics, etc.); antipsychotics (phenothiazines); and anti-anxiety medicines (benzodiazepines).
- Photodermatitis causing allergic reactions may be observed after using certain perfumes; sunscreens containing PABA; Industrial/anti-bacterial cleaners or soaps containing hexachlorophene, salicylanilide; and certain plants with allergen components/compounds (limes, parsley, lemons, celery, parsnips, wild carrots, and figs)

The susceptibility to occurrence of photodermatitis may also increase in case of below listed triggers or risk factors:

Patients with porphyria are at increased risk
Contact with sunlight for more than 30 minutes, more so in spring and summer
Exposure to bright sunlight that occurs between 10 AM and 2.30 PM; about 50% of UV sunlight radiation gets emitted during this period.
People with fair or pale skin, green or blue eyes, or red or blonde hair have increased sensitivity to ultraviolet rays; this factor is not dependent on race or ethnicity. The incidence rate of photodermatitis in African-Americans and Caucasians is almost the same.

Treatment of photodermatitis

Photodermatitis is a mild condition and patients recover quickly with minimal treatment.

If photodermatitis occurs due to some unexpected reaction, then clean skin rash with cold water to remove allergic agents. Cold water can also help find relief from itching, etc.
Blistering or lesions that ooze need to be covered with wet and cool dressings.
Calamine lotions and antihistamines can alleviate itchiness.
Phototherapy, i.e., regulated exposure of skin to light for decreasing skin sensitivity and controlling symptoms, may be used for treating certain forms of photodermatitis. Doctors may suggest medicines like hydroxychloroquine, thalidomide, beta-carotene, or nicotinamide if phototherapy is not possible.
Short-term dosage of glucocorticoids may help manage outbreaks.
Severe sensitivity to sunlight may require immune system suppression via drugs like azathioprine.
Consult doctor for alternative medicines if photodermatitis is triggered by use of certain drugs.
If photodermatitis is triggered by nutritional deficits, then intake of a healthy, balanced diet along with supplements can help alleviate symptoms. Flavonoids and antioxidants are vital nutrients that protect skin from UV rays damage.

Follow the self-care guidelines listed below to prevent photodermatitis:

Apply sunscreen with at least 30 SPF before going outdoors. Sunglasses, hats, shirts/tops with long sleeves, long pants, and other options to protect skin from UV rays are also recommended.
The period between 10 am to 2 pm has the brightest sunlight. Avoid going outdoors during this time.
Do not use tanning devices like a tanning lamp or a tanning bed
Do not use cosmetics or other skin care products that raise skin sensitivity to UV rays.