New Research Sheds Light on “Sun Allergies”
A recent study conducted by dermatologists at the Vanvitelli University of Naples has found that “sun allergies” are not actually allergies to the sun itself, but rather conditions of hypersensitivity and intolerance of the skin to the sun’s rays. These conditions often manifest themselves as itchy skin rashes.
According to Giuseppe Argenziano, a full professor of dermatology at the university and president of the Italian Society of Dermatology and Sexually Transmitted Diseases, having a light phototype (skin type) is a risk factor for these reactions, but they can affect all skin types. The exact causes of these reactions are still not well understood, but there may be a genetic predisposition or the reaction could be triggered by the use of certain drugs, particularly antibiotics, or by cosmetic products containing chemicals.
The most common form of what is commonly referred to as “sun allergies” is polymorphic solar dermatitis. While it affects both sexes, women are more prone to this condition. The age group most affected is typically between 20 and 50 years old.
Symptoms of polymorphic solar dermatitis include small reddish itchy bumps on parts of the body that are not typically exposed to the sun throughout the year, such as the shoulders, neck, and chest. However, the skin in the most exposed areas has developed a tolerance to the sun’s rays. These symptoms usually appear a few hours or days after intense exposure to ultraviolet rays but do not leave scars once treated and healed. Other possible symptoms, when associated with the skin papules, include fever, headache, tiredness, and low blood pressure.
To diagnose this form of dermatitis, it is recommended to consult a dermatologist who can conduct a photosensitivity test. If the test is positive, the dermatologist may then prescribe a treatment with cortisone cream and antihistamines. In addition to pharmacological therapy, it is crucial to wear protective clothing, including a hat and sunglasses, and to use creams that shield the skin from ultraviolet rays. It is also advisable to seek shade during the hours when the sun’s rays are stronger, typically from 10 a.m. to 4 p.m.
While polymorphic solar dermatitis is the most common form, there are other forms of solar allergies, although they are much less frequent. These include solar urticaria, which appears about 30 minutes after intense exposure, and actinic prurigo, characterized by the formation of papules that can develop into plaques or nodules. Another form, known as photoallergic dermatitis, is triggered by the interaction between sunlight and certain chemical substances found in drugs or cosmetics or by exposure to certain plant substances. These reactions are considered true allergies and can be identified through a photopatch test. The best way to prevent these reactions is to avoid the use of the responsible substances.
Argenziano also noted that even sunburn can be considered a mild form of “allergy,” which eventually disappears as the skin tans.
In conclusion, understanding the different forms of “sun allergies” and taking preventive measures, such as gradual exposure to sunlight and the use of protective clothing and creams, can help individuals avoid these uncomfortable and often itchy skin reactions.