What is Photosensitivity?
Photosensitivity is a term used to describe a range of symptoms, diseases, and conditions that may be worsened or triggered by exposure to sunlight.
Photosensitivity refers to a variety of conditions that affect a person’s sensitivity to solar ultraviolet (UV) and/or visible radiation. When people with normal skin are exposed to UV radiation (UVR), they may experience sunburn, tanning, and immunosuppression in the short term, as well as photo carcinogenesis in the long term. However, individuals with photosensitivity may experience abnormal skin reactions even with low levels of sunlight exposure.
Who gets photosensitivity?
Photosensitivity is a condition that can affect people of all races and ages, regardless of gender. The type of photosensitivity one experiences may vary depending on their stage of life. Both genetic and environmental factors can contribute to the condition. Fair-skinned individuals with Fitzpatrick skin type 1, who do not tan easily in the sun and have red hair and blue eyes, are often considered more photosensitive compared to those with darker skin who tan more readily. However, it is worth noting that not all fair-skinned people with Fitzpatrick skin type 1 have photodermatosis.
Classification of photosensitivity
Photosensitivity disorders can be subdivided into four broad categories:
- Idiopathic/immune-based dermatoses:
The reasons behind idiopathic photodermatoses remain unknown. Sun exposure results in a distinct medical condition.These include:
- Polymorphic light eruption
- Juvenile spring eruption
- Actinic folliculitis
- Actinic prurigo
- Solar urticaria
- Chronic actinic/photosensitivity dermatitis
- Hydroavacciniform (associated with Epstein-Barr virus)
- Drug and Chemically induced reactions, including those exogenously mediated and the cutaneous porphyrias:
- Certain medications can make your skin more sensitive to sunlight, known as photosensitivity. Drugs that can cause this include thiazides, tetracyclines, NSAIDs, and more. Exposure to phototoxic chemicals can also cause skin reactions. It’s best to consult with your healthcare provider to stay safe while taking these medications.
Disorders associated with defects in DNA excision repair:
- Xeroderma pigmentosum
- Bloom syndrome
- Rothmund-Thomson syndrome
- Cockayne syndrome
- Hartnup disease (see Pellagra)
- PhotoaggravatedDermatoses, a wide range of disorders that may be worsened by light exposure:
- Lupus erythematosus
- Dermatomyositis
- Darier disease
- Rosacea
- Pemphigus vulgaris
- Pemphigus foliaceus
- Atopic dermatitis
- Psoriasis.
Clinical evaluation:
When identifying certain conditions, consider age, family and medication history. It’s helpful to know sunlight exposure duration, rash onset time, and resolution time. Symptoms include itch and pain after light exposure and can vary in appearance. Photosensitivity occurs in spring to autumn months but severe cases happen year-round. Symptoms induced by window glass exposure are likely due to UVA or visible light, not UVB.These eruptions tend to occur on light-exposed skin, often with sharp cut-offs where clothing or watch straps have protected the skin.
What causes photosensitivity?
Photosensitivity is caused by an abnormal reaction to some component of the electromagnetic spectrum of sunlight and a chromophore (reactive compound) within the skin.
The electromagnetic spectrum ranges from cosmic rays, invisible rays called ultraviolet radiation (UVR), through visible light, to infrared, microwaves, and radio waves. UVR has 3 portions
- UVC: ultrashort wavelength rays 200–290 nm that do not reach the earth’s surface
- UVB: short-wavelength rays 290–320 nm that cause sunburn and tan
- UVA: longer wavelength rays 320–400 nm that cause tanning and also suppress immune reactions in the skin
Patients can be sensitive to one kind of sunlight (i.e. only to UVB, UVA, or visible light) or to a wider range of radiation. The most common photosensitivity is to UVA.
What are the clinical features of photosensitivity?
The clinical features depend on the specific photodermatitis.
- Photodermatoses affect sun-exposed areas like the face, neck, and hands, but not usually covered areas like those protected by clothing.
- In cases of polymorphic light eruption, it is common for affected individuals to avoid exposing certain areas, such as the face, to sunlight.
- At times, these conditions may only impact specific areas of the body. For example, juvenile spring eruption typically only appears on the tops of the ears.
- It is possible to develop photodermatoses from exposure to artificial sources of UVR (such as fluorescent lamps) or visible radiation indoors.
If you have a rash on an exposed area, there could be another reason for it. For example:
- Acne on the face is caused by the blockage of hair follicles due to a buildup of sebum and keratin.
- Contact dermatitis due to makeup applied to the face
- Airborne contact dermatitis due to plant pollens, such as sesquiterpene lactone.
Clues to photosensitivity include:
- Photodermatoses can worsen in summer or happen any time of year.
- There is a clear distinction between the impacted region and the skin that is concealed by clothing or accessories such as a watch band or ring.
- Sparing of folds of upper eyelids
- Sparing of deep furrows on face and neck
- Sparing of skin covered by hair
- Sparing of skin shadowed by the ears, under the nose, and under the chin
- Sparing of the web spaces between the fingers
How is photosensitivity diagnosed?
Photosensitivity is diagnosed by looking at a person’s medical history and conducting skin tests.
Photo tests are used to test photosensitivity by exposing small areas of skin to different light sources and doses. This helps determine if a rash can be replicated and if sunburn occurs more easily than expected. These tests are only available at specialized facilities and can be difficult to interpret.
To test for photosensitivity, doctors apply adhesive patches with known photosensitizing materials to the upper back. After two days, the patches are removed, and the area is exposed to light. Any reactions are observed two days later.
What is the management for photosensitivity?
Protect yourself from photosensitivity by avoiding natural and artificial UVR exposure. Check UV levels with websites or apps in high-risk areas. Prioritize protection during midday, especially in summer and high altitudes. Ensure your safety.
- Avoiding exposure to direct sunlight
- Staying indoors and away from windows, and seeking shade when outdoors
- Dressing up in covering clothing and wearing a wide-brimmed hat when outdoors.
- Broad-spectrum sunscreen SPF 50 or higher, covering all exposed skin.
What is the homeopathic management for photosensitivity?
In every case, homeopathic medicines are chosen based on individual symptoms. They are effective for both acute and chronic instances of photosensitivity. These medicines are derived from natural substances and are safe for people of all ages. Some common medicines used to treat this condition include:
- Aconitum napellus . For a sudden rash, when the person feels anxious, frightened, and restless. Symptoms may occur after exposure to cold, dry wind or sunlight. If a sudden rash develops and the person experiences extreme anxiety and apprehension, this remedy may be appropriate.. Exposure to sunlight, or being out on a cold, dry, windy day, may precipitate symptoms. The rash may feel numb or itch, and stimulants may reduce the itching.
- Belladonna.If you experience a sudden rash accompanied by a feeling of heat, and your face appears flushed and burns, Belladonna can be a helpful remedy, particularly for sunstroke.
- Natrum carbonicum . If you have a rash that appears in patches and feels like blisters, it could be a result of exposure to the sun. You may also experience a general feeling of illness. It’s possible that you are sensitive to changes in the weather and may be allergic to milk..
- Natrum muriaticum. If you experience fatigue, headaches, and a blotchy, itchy, or burning rash after being in the sun, you may be suffering from sun poisoning. You may also feel thirsty and have a desire for salt. These symptoms are usually more severe in the morning..
If you experience a burning sensation with blisters, Cantharis can help soothe it.
