Sun Allergy – Causes, Symptoms & Treatment

Sun allergy

The sun allergy or photo allergy is a colloquial collective term for all skin problems that arise or are favored by sunlight. In a narrower sense, sun allergies can be described as photodermatoses, since they affect the skin, which reacts to exposure to sunlight. In a broader sense, various metabolic diseases or autoimmune diseases are also popularly referred to as sun allergies. Symptoms of various kinds from itching to redness to serious changes in the skin appear in connection with sunlight.

What is sun allergy?

sun allergy (photoallergy) is an umbrella term for the occurrence of skin problems caused by exposure to light. They occur over a period of a few hours to a few days and manifest themselves in the form of redness , wheals, nodules, blisters and scarring, pustules and thickening.

In addition, those affected by the sun allergy experience extreme itching and severe burning . However, these symptoms can vary greatly, since sun allergy is not a disease as such, but has various causes. An accurate diagnosis must be made to allow treatment of sun allergy.


Sun allergy is rarely an allergic reaction to sunlight itself. Rather, causes such as allergies to other substances, autoimmune diseases or metabolic disorders play a role. The most common are polymorphic light eruption (PLD) (strain on skin not used to light), “Mallorca acne ” (similar to PLD but slightly different appearance) and photoallergic reactions.

For example, in the case of a photoallergic reaction, a sun allergy turns out to be meadow grass dermatitis, a skin reaction to certain meadow grasses in combination with exposure to light. Here the light is perceived as the cause, but is actually only one component of the overall reaction.

A sun allergy can also occur as an overreaction of the skin to unusual exposure to UV-A or UV-B radiation. Other explanatory models attribute the development of a sun allergy to free radicals. The cause of the sun allergy must therefore always be determined individually in each individual case.

Sun allergy is rarely a true allergy. Much more often, the respective diseases are due to the fact that the skin reacts intolerantly to sunlight or certain rays that it contains. As already mentioned, the skin reacts particularly frequently to various forms of UV radiation. Polymorphic light eruption, also known as Mallorca acne, is a classic type of sun allergy – skin changes occur in different parts of the skin due to the effects of UV-A and UV-B rays.

In the case of the autoimmune disease lupus erythematosus , which is also known as sun allergy, the changes in the skin often appear more severely when it has been exposed to sunlight. Sunlight also causes other symptoms in those affected, such as headaches or fever . The metabolic disease porphyria is also not an allergenic reaction; people only react to sunlight with increased sensitivity and can feel pain without the sunlight visibly harming them.

Symptoms, Ailments & Signs

A sun allergy – which is actually not a classic allergy at all – is accompanied by itching and other skin changes, such as blistering and pustules . Symptoms can also appear hours or days after being in the sun.

Depending on the person, the symptoms appear differently, but always the same in repeated cases. Fair-skinned people are affected more often than dark-skinned people. The skin begins to itch and burn. Another sign is skin reddening in the form of reddish spots. The development of nodules, vesicles or even actual blisters is also a symptom and at worst the skin swells up.

Sun allergies often occur when the skin has not been exposed to the sun for a long time. This means that this disease occurs especially in spring or summer. However, this is also possible on holidays abroad with different climatic conditions than at home in both summer and winter.

Body parts that were covered in winter or in the colder season are now exposed to the sun. This mainly affects the neck, décolleté, arms, backs of the hands and legs. Since the face is not covered either in the cold or in the heat, the sun allergy occurs less here.


Excessive exposure to the sun despite a sun allergy can cause symptoms and complications. In addition to the typical skin irritations – itching, redness, blistering – burns and severe inflammation can also occur. Accompanying this, allergic symptoms such as watery eyes occasionally occur.

In severe cases, visual disturbances such as loss of visual field and blurred vision can occur. Further complications arise if these complaints are not treated. The skin changes can develop into serious infections or chronic pain can develop. After a long stay in the sun, scars or pigment disorders occasionally appear.

Typical treatment methods such as photochemotherapy also carry risks. In connection with light therapy, inflammation of the cornea and conjunctiva occurs again and again. Liver spots and pigment disorders also occur. Exposure to light causes the skin to age prematurely and wrinkles and other cosmetic blemishes to form.

Headaches, dry mouth, and drowsiness may occur after taking antihistamines. In addition, regular use of the preparation can lead to serious kidney and liver damage. Serious complications arise from overdose or drug interactions or existing medical conditions.

When should you go to the doctor?

Changes in the appearance of the skin must always be presented to a doctor. If there is pain on the skin, the formation of spots or an unpleasant itching, it is advisable to clarify the cause. If open wounds develop from scratching the affected skin areas or if there are signs of inflammation, a doctor is needed. There is a risk of blood poisoning if wounds are not treated sterilely. This is potentially life-threatening and should be examined by a doctor as soon as possible.

Nodules on the skin, blisters or discomfort when touched should be examined by a doctor. Of particular concern is when symptoms continue to increase or multiply with exposure to sunlight. A doctor should be consulted in good time, since a sun allergy often leads to a rapid increase in symptoms and well-being decreases significantly. With adequate medical care, relief of the symptoms is initiated.

Swelling, redness of the skin, and difficulty moving or resting are signs of a health condition that should be discussed with a doctor. The sun allergy usually occurs on the back of the hand or the legs of the affected person. If items of clothing cannot be worn without symptoms or if there is a decrease in physical performance, help should be sought.

Treatment & Therapy

If there is an acute sun allergy, the extreme irritation of the skin must first be reduced. Cortisone preparations such as ointments and creams are used for this purpose. In extreme cases, internal use via tablets is also an option. Usually this cortisone treatment is kept as short as possible because cortisone can cause significant side effects.

There is no one-size-fits-all treatment for sun allergy symptoms. Depending on the underlying disease, different treatments are required. Sometimes the changes in the skin are treated directly, in other cases that would be of little use, which is why the individual disease must be combated above all.

Allergic flare-ups, which are fought with antihistamines, can play a role in polymorphic light eruption. However, these only help with real sun allergies, with all other forms they remain ineffective. Various medications can be prescribed to treat the changes in the skin. To combat blackheads caused by sunlight, cream containing cortisone is used, for example.

In the case of autoimmune diseases or metabolic disorders, changes in the skin are treated individually, since these are not blackheads but reactions. However, the accompanying treatment of the underlying disease is important. In the case of autoimmune diseases, an attempt is always made to prevent the immune system from reacting defensively to the respective influence, which should also alleviate the symptoms. The same treatment principle also applies to metabolic diseases that are considered sun allergies.

Nevertheless, long-term treatment with lighter preparations cannot always be avoided in patients with frequent skin problems. If irritation is present, the skin must be protected from further irritation. Intensive sun protection using products with UV filters and protecting the skin with clothing that covers it as much as possible are important means of protecting the skin.

In the case of very severe skin irritation, the administration of antibiotics may be necessary, since germs could penetrate through open skin injuries (e.g. scratched pustules) and penetrate the irritated immune system. In addition to freeing the skin from irritation and regenerating it, the causes of the sun allergy must be clarified and treated.


The development of diseases known as sun allergies can hardly be actively prevented. Autoimmune diseases in particular develop independently of factors that the patient can influence himself. The symptoms of the respective diseases, on the other hand, can be prevented much better. As a general rule, it is best to stay away from sunlight whenever possible if it is harmful to the skin.

Some extreme manifestations even require this in order to largely avoid worse symptoms of the disease. In less severe cases, you can go out into the sunlight, but you should make sure you have effective protection against UV radiation. An effective sunscreen is the absolute basic requirement for staying in direct sunlight.

Since the acute treatment of sun allergy can be lengthy and the symptoms are distressing for the patient, the major part of their treatment lies in prevention. Above all, this means protecting the skin from intense or prolonged exposure to radiation. Constant use of UV protection and the best possible protection through clothing are advisable, because constant avoidance of the sun is neither possible nor really effective in the long run, as the skin becomes more and more sensitive.

The intake of carotene has a positive effect on the skin’s own protection, but must be supervised by a doctor, especially in the case of smokers. In addition to skin protection, the skin can slowly get used to the light (desensitization). This is usually done by therapeutic irradiation of the skin under medical supervision.


As a rule, the measures and options for direct aftercare in the event of a sun allergy are significantly limited, although in many cases they are not even available to the person affected. Therefore, the person affected with this disease should definitely consult a doctor at an early stage and possibly initiate treatment, since self-healing cannot occur in this case.

In general, those affected by the sun allergy should definitely avoid direct sunlight and protect themselves particularly well against the sun. Sun creams and various ointments should be applied to protect the skin from the sun. Direct exposure to the sun should also be avoided.

Those affected by sun allergy are advised to have regular check-ups and examinations carried out by a doctor in order to identify and treat possible skin cancer and other skin problems at a very early stage. It may also be necessary to take various medications for sun allergies. It is always important to ensure that it is taken regularly and that the dosage is correct. The sun allergy itself usually does not reduce the life expectancy of the affected person.

You can do that yourself

People with a sun allergy should protect themselves adequately from the effects of UV light. Direct sunlight on the skin or body of the person affected should be completely avoided in everyday life. Wearing clothing that provides good skin and head coverage is advisable. Loose, long clothing that fully covers the limbs is recommended. If possible, an umbrella or a slightly larger headgear should be used so that the face is also adequately protected.

In addition, the skin must be provided with a care product. A sunscreen with an SPF or a product prescribed by a doctor is recommended. The latter is often tailored to the needs of the person concerned and is therefore individually manufactured.

The first allergic reactions of the organism should be reacted to immediately. Visiting places in the shade is essential. It is important that those affected develop various strategies to protect themselves from sudden and unexpected sun exposure in everyday life. When leaving the house, clothing or objects should be taken with you as a precautionary measure, which can also serve as protection against sunlight. In everyday life, places with little shade, such as going to the beach, should be reduced to a minimum or only take place after sunset.

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.