Photoallergy phototoxicity

Certain chemicals can produce skin reactions, induced by light, after their topical application to the skin or systemic administration into the body. There are two distinct types of photoreaction phototoxicity and photoallergy. Phototoxicity is the more common photoreaction, with the appearance of sunburn and hyperpigmentation. The reaction can occur from the first exposure to the toxicant and usually requires a high dose of the substance. Photoallergy is a light-induced immune reaction that occurs from reexposure to the toxicant following an incubation period after the first exposure. The... 

As public consciousness of the harmful effects of exposure to ultraviolet light (skin cancer, premature ageing, etc.) has increased, there has been a substantial increase in the use of sunscreens. These sunscreens have, however, been associated with a number of reported problems such as phototoxicity and photoallergy. The use of p-aminobenzoic acid (PABA) and its derivatives has been discontinued due to their ability to... 

Photosensitivity Photosensitization (photoallergy or phototoxicity) may occur therefore, caution patients to take protective measures (ie, sunscreens, protective clothing) against exposure to sunlight or ultraviolet light (eg, tanning beds) until tolerance is determined. 

Porphyria In patients with porphyria, these drugs have precipitated an acute attack. Photosensitivity Photosensitization (photoallergy or phototoxicity) may occur. Renal/Hepatic function impairment Jse with caution. The frequency of renal complications is considerably lower in patients receiving the more soluble sulfonamides (sulfisoxazole and sulfamethizole). 

Photosensitization word used to describe either photoallergy or phototoxicity. 

Additional considerations for inhalation/intranasal route acute inhalation, application site, and pulmonary sensitization studies for parenteral route acute parenteral toxicity and application site studies mucosal use application site evaluation transdeimal and topical drugs application site and phototoxicity/photoallergy evaluation. Photocarci-nogenicity is a conditional option for transdeimal and topical excipients. 

Chlorpromazine PZ- Phototoxicity, photoallergy, ocular damage Anti-psychotic [53]... 

In animal study it was reported that 89% of the mice fed PPD developed lenticular changes indicating that PPD has cataractogenous effects, which are related to the duration, amount and individual sensitivity [49]. It was concluded that PPD is potentially toxic to human lens. Exophthalmia and permanent blindness due to optic nerve atrophy following PPD poisoning were reported [6]. Using a patch test to determine PPD phototoxicity, it was proved that PPD could cause a phototoxic reaction and photoallergy [50- 51]. 

Epstein JH (1999) Phototoxicity and photoallergy. Seminars in Cutaneous Medicine and Surgery 18(4) 274—284. 

Safety testing for cosmetics includes usually cumulative irritation, RIPT, phototoxicity, photoallergy, and finally, exaggerated use or home use studies. 

Tests to study phototoxicity and/or photoallergy usually involve 25 subjects with test material bearing patches applied in duplicate one set does not receive radiations while the second set is irradiated. In phototoxicity, patches are applied for 24 h. The irradiated patch is exposed to 16Jcm UVA and 0.75 MED (minimum erythema dose) UVB. All sites are evaluated at 1, 24, 48, and 72 h following exposure. 

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