What Are The Signs Of Photosensitivity?

A bright sunny day can be an instant pick-me-up and put a spring in your step. But if you find yourself breaking out in hives, rashes, or painful lesions every time you head out in the sun, you may just be photosensitive. Here’s how you can spot the signs and find out whether you are having a reaction to a drug, showing signs of an underlying illness, or just plain allergic to sunlight.

How Do You Know If You Are Photosensitive?

Spotting the signs of photosensitivity may seem obvious, but unless you have an acute case of photodermatitis, you may not notice right away. Here’s a quick roundup of signs to watch out for, to tell if you have a “sun allergy.”1

  • Bumps, raised patches of skin, lesions, or blisters on the body, and typically quite itchy
  • Dark patches of skin or hyperpigmentation
  • Fever, headaches, nausea, and chills
  • Problems confined to parts of the skin that are exposed to sunlight

Over time, the skin may also begin to scar as a result of these bumps and lesions. It could also start to thicken up.

Getting Diagnosed

It is important to get yourself diagnosed, not just for the aesthetic changes you will see, but to treat underlying causes if any. Even if it is just an allergic reaction to the sun, leaving it unchecked can cause permanent scarring. For those whose photosensitivity is inherited through their genes, the condition may increase the risk of skin cancer, requiring specific care and possible follow-ups with the doctor.2


Is It A Sun Allergy?

When you have an allergic or immune reaction to sunlight, you may see signs of it right after you go out or even a day or two later. Symptoms may last for several days. In reality, not everyone has what’s called a “true” allergy to sunlight, also known as solar urticaria. This skin reaction, occurring more in women than in men, results in red or pink swollen patches that the National Health Services compares to nettle stings. When you come into the shade and away from the sun, these rashes and patches disappear almost immediately, usually in under an hour. Once clear, the skin returns to normal, with no visible signs of the reaction in cases of a mild outbreak. For more severe cases, antihistamines may be needed.3

A condition that affects more people is polymorphous light eruption (PMLE), which can sometimes be mistaken for solar urticaria. Some medical professionals now believe it may be a form of delayed allergic reaction. For people with this condition, it is not just sunlight but even artificial light – as you would find in tanning salons – that can set off reactions. The ultraviolet A (UVA) radiation causes the skin to develop a rash or other reactions as late as a day after exposure. There may also be small blisters, painful rashes, itchiness, red bumps, and patches that are red and even quite big.4


Spotting Photosensitivity Due To Underlying Diseases/Disorders

You may also see some specific symptoms due to underlying conditions or disorders called photo-aggravated diseases. For instance, those with lupus-linked photosensitivity may develop hive-like rashes. Others with lupus may get a butterfly rash that spans the cheeks and nose area, creating a butterfly-shaped pattern. Exposure to sunlight may also worsen lupus symptoms and bring on joint pain and fever, and in some cases inflammation of internal organs. So if you are among the two-thirds of those with lupus who have heightened sensitivity to the UV rays present in sunlight and artificial light, extra care will be necessary.5 In one study a whopping 83 percent of test subjects with lupus had photosensitivity, whether mild or acute. About 69 percent showed particular reactions to sunlight exposure, which worsened their symptoms.6

For those with photosensitive psoriasis, symptoms of psoriasis will typically improve in dark wintry months, when there is little to no sunlight exposure.7 Other conditions like atopic eczema, rosacea, pemphigus, dermatitis herpetiformis, and viral exanthemata can also cause your skin to become sensitive to light.8


Symptoms Of Drug-Induced Photosensitivity

If you’ve recently started taking new medication and simultaneously see symptoms of sensitivity to light exposure, it could be due to phototoxicity or photoallergic reactions. Signs of phototoxic reactions to watch out for include severe sunburn that may even cause the skin to peel, erythema or redness of exposed skin, and pain and/or a prickly or burning sensation. These signs begin to show up quickly anywhere from 12 to 24 hours after you have exposed your skin to sunlight. Because this is not an immune reaction, you may react to a drug you have used before or been sensitized to already. For photoallergic responses, however, symptoms may be more eczema-like, with dermatitis and solar hives, as well as redness from erythema. You may simply need to discontinue the drug and ask your doctor to prescribe an alternative, to overcome the photosensitivity.9