Causes and risk factors
Causes include exposure to harmful ultraviolet rays of the sun. Sunrays contain visible light and invisible light known as UV rays. There are several factors which can predispose one to photosensitivity such as – exogenous – photosensitivity is caused by external agents that are applied locally or taken internally – like medicines, drugs, contact with certain plants, chemicals, or foods, etc. They are called as photosensitizers. Metabolic – disturbance in metabolism causes photosensitivity such as porphyria, i.e., increased porphyrin in the skin – porphyria cutanea tarda, erythropoietic porphyria. Photo-exacerbated photosensitivity – photosensitivity due to existing skin disease – SLE, psoriasis, rosacea. Genetic – photosensitivity in preexisting genetic disorder such as Bloom syndrome, xeroderma pigmentosum.
Clinical presentation
Patient presents with red rash, blisters, or wheals. There can be itching on the affected areas, burning skin, and eczema. The affected area is warm to touch.
Investigation
Medical history by the patient and clinical examination by the dermatologist helps in diagnosis. Photopatch test confirms the diagnosis. This test involves 2 techniques, i.e., patch test for allergic contact dermatitis and photopatch test. In photo patch test, additional patches are applied to skin. When these are removed, they are exposed to small dose of long wave UV light and the rash appears.
Treatment
Main goal of treatment is to identify the photosensitizing agent. Wearing protective clothing to cover skin will help in managing photosensitivity. Use of sunscreen within proper SPF limits contributes further to the treatment.
Other Modes of treatment
The other modes of treatment can also be effective in treating photosensitivity. Homoeopathy is a science which deals with individualization and considers a person in a holistic way. This science can be helpful in combating the symptoms. Similarly, the Ayurvedic system of medicine which uses herbal medicines and synthetic derivates is also found to be effective in treating photosensitivity.
