Drug-Induced Photosensitivity

Drug-Induced Photosensitivity

Key Points
Exaggerated Sunburn caused by a combination of sunlight and certain drugs or chemicals
Common
Rashes or blisters may develop

Drug-induced Photosensitivity is caused by the combination of certain drugs (topical or oral) or chemicals and exposure to sunlight. The result can be an unexpected Sunburn or a dry, bumpy, or blistering rash (itchy or not itchy) on parts of the body exposed to the sun. Such medications can include antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDs), Diuretics, Retinoids, Hypoglycaemics, Neuroleptics, PDT Pro-photosensitisers, as well as certain sunscreens, herbal products, and fragrances. A Photosensitivity reaction should be considered in patients experiencing sunburn of greater severity than would normally be expected for them, or who develop rashes in areas exposed to the sun or tanning apparatus.

Drug-induced Photosensitivity reactions are common and can occur to anyone at any age. Those who sunburn easily are more predisposed. The reaction can be phototoxic (causing damage to the skin when exposed to light) and/or photoallergic (an allergy that is activated by light).

Differential Diagnosis (Other conditions with similar appearance)

Contact Dermatitis
Lichen Planus
Drug eruptions
Lupus erythematosus

Diagnosis
A drug history is taken and combined with a visual inspection of the skin, checking for changes in the skin characteristic of phototoxic drug eruptions: abnormal redness, swelling, and blisters.

Treatment
Treating Drug-induced Photosensitivity involved identifying the offending drug or chemical and discontinuing its use. If the drug or chemical cannot be discontinued, then the patient should protect him or herself from the sun by using ample sunscreen and wearing long sleeves and other sun-protective clothing.

"duce DRESS syndrome include Phenobarbitol, Carbamazepine, Phenytoin, Lamotrigine, Minocycline, Sulfonamides, Modafinil Dapsone and, especially, Allopurinol.

Differential Diagnosis (Other conditions with similar appearance)

Acute Febrile Neutrophilic Dermatosis
Measles,
Contact Dermatitis,
Pityriasis rosea
Porphyria cutanea tarda
Erythema multiforme
Psoriasis
Erythema nodosum
Erythroderma
Syphilis
Gianotti-Crosti Syndrome

Diagnosis
Key Points
High fever
Skin Rash
Organ inflammation
Abnormal liver function

Diagnosis is made based on the symptoms exhibited by DRESS: High fever, skin rash, and organ involvement. Confirmation can be made by findings of increased white blood cells in the blood and abnormal liver function.

Treatment
Discontinue the affecting drug
*Treat the symptoms

To treat DRESS, the patient needs to discontinue the use of the affecting drug as soon as possible. Once the patient stops taking the drug, the symptoms may then need to be treated. Because the death rate from DRESS is relatively high (8 percent), blood tests should be administered and Systemic steroids such as Prednisone should be prescribed in severe cases, especially where the patient is losing skin or suffering from pneumonia or hepatitis.

If DRESS is triggered by any one of these three medications — phenytoin, carbamazepine and phenobarbitone — the other two should not be prescribed as an alternative, as though who experience DRESS will be similarly affected by all three medications.