Sun allergy: symptoms and what to do?

Sun allergy is used colloquially and describes various noticeable skin changes that can occur with UV radiation. Anyone who is affected by the typical symptoms such as a rash and itching wonders which home remedies and remedies can be used for sun allergy and whether it can be prevented. What different diseases are hidden behind the term, how can you recognize the different forms of sun allergy from pictures and what helps against sun allergy?

Sun allergy: what is it?

A sun allergy is not an actual allergy, like hay fever. Instead, different diseases are summarized under this term, in which there are skin reactions due to UV radiation.

If a person suffers from a sun allergy, the sun’s UV rays trigger bodily reactions, which in turn cause burn or allergy-like symptoms on the skin. This is probably due to processes in which aggressive oxygen particles (free radicals) are released in the body due to the effects of UV radiation, which have a cell-damaging effect. As part of a protective reaction, the body releases the messenger substance histamine, which causes the skin vessels to dilate and thus causes warmth, redness and itching.

Only parts of the body that are exposed to the sun are affected. This includes, for example, the neck, upper arms, hands and décolleté.

One should not confuse a sun allergy with so-called heat rashes. These can appear in different forms on the skin and are accompanied by severe itching. However, they have nothing to do with the influence of sunlight but rather with heavy sweating, which clogs the skin’s pores.

 

Sun allergy: symptoms and causes

Sun allergy is a collective term that includes various skin changes. Depending on the disease, there may be slightly different symptoms. In general, there are a large number of skin diseases that are triggered by UV light (photodermatosis). The most common forms are presented below.

Polymorphic Lichtermatosis

Polymorphic light eruption (PLD) is the most common form of sun allergy. As a rule, PLD is, therefore, meant when colloquially speaking of a sun allergy.

Women are affected by this condition more often than men. It is also more common in people with fair skin and light hair. The skin reactions usually show up in areas heavily exposed to the sun, such as the arms, the backs of the hands or the décolleté. The face can also be affected, particularly the nose or forehead.

The symptoms of this type of sun allergy can differ for different people, but they are always the same for the same person. Typical symptoms are:

• itching
• blisters or patchy skin rashes (hives)
• lumps or swelling of the skin
• weeping patches of skin

These signs usually do not appear immediately but only a few hours to days after the intense solar radiation.

Typically, the symptoms appear in spring and early summer – i.e., when the sun’s rays increase again, and the skin is more exposed to it. Symptoms tend to decrease throughout the summer as the skin adjusts to the sunlight and builds up more UV protection. However, polymorphic light eruptions can recur and cause symptoms for years.

Mallorca acne

Another clinical picture called sun allergy is Mallorca acne (Acne aestivalis). It is named after the popular travel destination, as the disease was first observed in those returning from Mallorca.

The symptoms of this type of sun allergy appear in papules about two to four millimetres in size, which are slightly raised. The rash is often inflamed and itchy. In contrast to regular acne, comedones ( blackheads ) do not form.

The fact that Mallorca acne is caused by fatty substances or emulsifiers in sunscreen or body lotion that react with UV radiation is now considered controversial. This form of sun allergy can also occur regardless of its use. With Mallorca acne, exposure to sunlight causes the hair follicles to close, resulting in a build-up of secretions. This, in turn, triggers the rash.

Phototoxic reaction

A phototoxic reaction involves skin irritation from substances that can develop a “toxic” effect when exposed to sunlight.

These include certain plant substances, namely the furocoumarins contained in some plants. Skin contact with the corresponding plants – for example, giant hogweed or angelica – can cause skin reddening, burning, itching or swelling. It is, therefore, also referred to as the so-called Wiesendermatitis. The symptoms are similar to severe sunburn.

However, it is also possible that substances in the body react toxically to sunlight. This is the case with skin changes caused by taking some medications. These contain specific molecules that absorb the energy from sunlight and then rerelease it to form free radicals. This damages the skin cells.

Anyone who has been prescribed medication such as St. John’s wort preparations, antibiotics, agents for drainage (diuretics) or against cardiac arrhythmias should inquire at a doctor’s appointment or in the pharmacy whether photoallergic or phototoxic reactions are among the possible side effects. Sun-related skin reactions, such as pigment changes, can also occur with the birth control pill . Generally, when taking medication, a look at the package insert provides information about undesirable side effects.

photoallergic reaction

The photoallergic reaction is a true allergy because the immune system is involved. A wide variety of substances – from fragrances in cosmetics to chemical light filters in sunscreens to medicines – can lead to an allergic skin reaction in combination with sunlight.

The following symptoms can show this:

• nodules or vesicles
• severe itching
• skin redness
• thickening of the skin
• furrows in the skin
• Formation of skin flakes

Photoallergic reactions usually only occur in people with other pre-existing allergies.

 

solar urticaria

Solar urticaria can be behind the skin reactions that occur in sporadic cases. Solar urticaria are hives caused by UV radiation. In contrast to polymorphic light eruption, the symptoms do not occur with a time delay but appear directly after contact with sunlight. 

In addition to the itchy wheals, symptoms such as headaches,  tiredness, or nausea can also occur. In the worst case, shortness of breath or an allergic shock is possible. The symptoms may arise because the body releases more histamine after contact with UV radiation.

Due to the life-threatening consequences of solar urticaria in the worst case, those affected should seek medical advice as soon as possible.

Sun allergy in children

A skin reaction triggered by UV radiation is widespread in children. Their skin’s UV protection has yet to be so strong. Therefore, babies and small children should be exposed to the midday sun less than possible. Children should spend more time outdoors in the shade. In addition, sufficient sun protection in the form of headgear, clothing (with UV protection) and sunscreen should be ensured.

In children, a sun allergy often manifests in wheals, blisters or spots, usually accompanied by itching. Nodules can also appear in adolescents.

What to do if you are allergic to the sun

If you suffer from a sun allergy, a dermatologist should first clarify its form and whether there could be triggers behind the symptoms, such as medication or herbal substances. The diagnosis is usually based on the query of possible triggers and the basis of the typical skin changes.

If it is a reaction to plant substances or drugs, it helps to avoid the cause in the future if possible and to change drug therapy if necessary. However, this should always be done in consultation with the treating doctor and not independently.

Depending on the extent and cause of the sun allergy, different aids can also be used.

 

Tablets, creams and other therapies for sun allergy

Special creams and ointments can help alleviate the symptoms of a sun allergy in the case of acute symptoms. These include creams containing cortisone or hydrocortisone and ointments based on antihistamines. Antihistamines can also be taken in tablet form, such as those containing the active ingredients cetirizine or loratadine. In the case of polymorphic light eruptions, they do not help against the skin symptoms themselves, but they can at least relieve the itching. For PLD, steroid creams can be used instead.

If solar urticaria is present, a targeted confrontation with sunlight can be used as medical treatment to achieve a habituation effect (“hardening”). Alternatively, photochemotherapy can also be used. The active ingredient psoralen is combined with UV-A radiation. This form of treatment, also known as PUVA therapy, is also used for psoriasis or neurodermatitis.

Home remedies for sun allergy

Home remedies can also bring relief for minor symptoms:

• Damp towels: Put damp towels from the refrigerator on the affected areas. These are warmer than an excellent pack from the freezer, which is why the cold stimulus does not additionally stress the skin.
• Quark wrap:  Quark can also cool and soothe the skin. To do this, take Quark out of the fridge and wrap a small portion in a clean kitchen towel. Avoid applying the curd directly to the skin, as this can cause infection if there are minor skin injuries.
• Aloe Vera:  Gels with aloe vera have a cooling effect and relieve itching and redness.
• Avoid the sun:  If you have acute symptoms, avoid the sun until the symptoms have subsided.

Does Calcium Help With Sun Allergy?

Calcium is said to inhibit the release of histamine and also help with the types of sun allergy in which an increased release of histamine is suspected. However, whether an increased calcium intake can help with the skin reactions mentioned is scientifically controversial.

Eating foods rich in calcium, such as dairy products, kale, spinach, or soybeans, certainly doesn’t hurt if you suffer from a sun allergy. An overdose of calcium through food is impossible since excess calcium is usually excreted with the stool.

Capsules or tablets with calcium should not be taken without medical advice if you are allergic to the sun to avoid overdosing on the mineral. According to the Federal Institute for Risk Assessment recommendation, the amount of calcium consumed via dietary supplements should not exceed 500 milligrams per day.

 

Prevent sun allergy

In the event of a photoallergic or phototoxic reaction, the trigger should be avoided if possible to prevent the symptoms. With all other types of sun allergies, it helps to get the skin used to the more intensive sun exposure as slowly and carefully as possible.

So avoid prolonged sunbathing right at the beginning of the warmer season and gradually increase the duration of your stay in the sun. You should also ensure that you wear clothing made of opaque material and always use sunscreen with a sufficiently high sun protection factor. This can also help increase the skin’s protection and help avoid sunburn.

In addition to the high sun protection factor, it is crucial to be safe when choosing sunscreen and to use a well-tolerated product without allergenic ingredients.