Photopatch test

Persistent photosensitivity developed in eight men after occupational exposure to hot epoxy resin fiimes. The condition was limited to sites contacted by the resin. Small doses of ultraviolet-A light evoked abnormal reactions consisting of erythema, edema, and papules in the clinically involved skin. Positive photopatch tests were observed to epoxy resin in four subjects and to bisphenol A in all subjects. Another study showed that bisphenol A can be released during the thermal decomposition of epoxy resin in the temperature range of 250-350°C. Photosensitizing activity was explained by the formation of ftee radicals during exposure to ultraviolet-B radiation of bisphenol A vapor, to form a semiquinone derivative of bisphenol A ... 

The methods for assessing reactivity previously outlined are simple, convenient, inexpensive, and noninvasive or minimally invasive 6 However, cutaneous reactivity depends on many factors. None of the previous methods give a full picture of the characteristics of sensitive skin, only susceptibility of skin to irritants. Subtle manifestations of endogenous cutaneous conditions must still be clinically excluded. Exclusion of allergic contact dermatitis must still be performed by patch testing, exclusion of contact urticaria by open tests or PUT/ROAT, and exclusion of photoallergy by photopatch testing. 

Patch testing (and photopatch testing) should document the few cases due to allergic contact dermatitis. Apart from the routine battery, testing should be performed with the fragrance and preservative series, as well as any cosmetic or skin care product that the patient uses. Immediate-type testing should be performed if indicated by the history. If systemic symptoms were present, perform only in the presence of emergency resuscitative facilities. 

Patch test and photopatch test — to rule out contact and photocontact allergy Immediate-type testing — to rule out contact urticaria... 

Pre-existing vesicular edematous cheilitis (probably due to contact allergy to the protecting lip salve) was aggravated after application of Zovirax cream (26). Patch tests to the lip salve were positive, but in addition there were positive photopatch tests to Zovirax cream, but not to its separate constituents. 

A 65-year-old man developed pruritic erythema on sun-exposed areas (photosensitivity) due to alprazolam (16). A photopatch test was negative, but an oral photochallenge test with UVA irradiation was positive after he had taken alprazolam for 17 days. 

Kurumaji Y, Shono M. Scarified photopatch testing in lomefloxacin photosensitivity. Contact Dermatitis 1992 26(1) 5-10. 

Martin-Lazaro J, Bujan JG, Arrondo AP, Lozano JR, Galindo EC, CapdevUa EF. Is photopatch testing useful in the investigation of photosensitivity due to flutamide Contact Dermatitis 2004 50(5) 325-6. 

The first published case of photosensitivity to formaldehyde was reported in 1982 in a man who developed pruritus, burning, and redness of the skin within minutes of exposure to sunhght photopatch tests showed specific photosensitivity to formaldehyde (13). 

The arylpropionic acid derivatives often cause allergic and photoallergic contact dermatitis, and photoallergic dermatitis to ketoprofen, with cross-photosensitivity to benzophenone and tiaprofenic acid, has been reported (188). Photopatch tests to these substances were positive but patch tests were negative. 

A case of photoallergic contact dermatitis from aceclo-fenac has been reported (189). Photopatch tests were positive with aceclofenac 10% in petrolatum, but not with either aceclofenac 1% or 5% in petrolatum or with a series of NSAIDs and other analgesics (benzydamine hydrochloride 3 and 5%, bufexamac 5%, diclofenac 1, 5, and 10%, fepradinol 1%, ibuprofen 5%, indometacin 1, 5, and 10%, ketoprofen 1%, naproxen 5%, paracetamol 1, 5, and 10%, phenylbutazone 1%, piroxicam 1%, salicylic acid 1 and 5%, and thiosalicylic acid 0.1%, all in petrolatum). 

Photocontact dermatitis has been reported after topical application of dexketoprofen (Enangel), with positive photopatch tests to dexketoprofen 1% and piketoprofen 2% (190). 

Local pharyngeal treatment with benzydamine hydrochloride 0.15% (Tantum verde) by a 67-year-old man resulted in systemic photocontact dermatitis in the third week of treatment (191). Photopatch tests with Tantum verde as is and in 10% aqueous solution were positive D1+, D2+, D3h—h. 

A photoallergic contact dermatitis followed topical administration of piketoprofen in a 46-year-old man after 3 days photopatch testing for piketoprofen was positive (1). 

A 30-year-old woman, a heterozygote for hypophosphatasia, who had been taking two tablets of a multivitamin formulation (pyridoxine hydrochloride 100 mg, riboflavin butyrate 30 mg, nicotinamide 40 mg, biotin 0.05 mg, ascorbic acid 100 mg) once daily for 6 years, had severe skin eruptions and pruritus on exposure to the sun. The minimum erythema doses for UVB (20 mJ/ cm ) and UVA (4 J/cm ) were lower than normal only for UVB (reference ranges 60-100 mJ/cm for UVB and below 10 J/cm for UVA). Patch and photopatch tests with the constituents of the tablets produced reactions to pjTidoxine and pjridoxal phosphate only. 

Lang PG Jr. Quinidine-induced photodermatitis confirmed by photopatch testing. J Am Acad Dermatol 1983 9(l) 124-8. 

A 51-year-old woman developed erythema and swelling on sun-exposed areas and complained of a local burning sensation and pruritus 10 days after she started to take rilmenidine 1 mg/day for mild hypertension. She recovered fully 1 week after rilmenidine withdrawal and treatment with prednisolone. The chronology and the results of patch and photopatch tests suggested a phototoxic reaction to rilmenidine. 

In a review of photopatch-testing in 2390 patients with rashes that were confined to sun-exposed areas, about 70% of 4374 positive reactions were classified as photo-induced reactions, of which 222 (5%) were photoaUergic reactions (6). NSAIDs, disinfectants, and phenothiazines were the main photoallergens. Photosensitive reactions to antimicrobial drugs, including topical agents, have been reviewed (7). 

British Photodermatology Group. Photopatch testing— methods and indications. Br J Dermatol 1997 136(3) 371-6. 

Neumann NJ, Holzle E, Plewig G, Schwarz T, Panizzon RG, Breit R, Ruzicka T, Lehmann P. Photopatch testing the 12-year experience of the German, Austrian, and Swiss photopatch test group. J Am Acad Dermatol 2000 42(2 Pt l) 183-92. 

Hasan T, Jansen CT. Photopatch test reactivity effect of photoallergen concentration and UVA dosaging. Contact Dermatitis 1996 34(6) 383-6. 

In 19 patients with positive photopatch tests to sunscreens among all the patients that were photopatch-tested between 1992 and 1999 (total not stated) there were 21 positive photopatch tests to sunscreen agents (3). Nine patients reacted to oxybenzone, eight to butylmethoxydibenzoylmethane, three to methoxycinnamate, and one to benzophenone. There were no reactions to para-aminobenzoic acid (PABA), reflecting the increased use of PABA-free sunscreens. Six patients also had positive patch tests to components of the... 

Berne B, Ros AM. 7 years experience of photopatch testing with sunscreen allergens in Sweden. Contact Dermatitis 1998 38(2) 61. ... 

Kroons S. Standard photopatch testing with waxter,para-aminobenzonic acid, potassium chromate and balsam of Peru. Contact Dermatitis 1983 9 5-9. 

Holzle, E., Neumann, N., Hausen, B., Przybilla, B., Schauder, S., Honigsmann, H., Bircher, A., and Plewig, G., Photopatch testing the 5 year experience of the German, Austrian, and Swiss Photopatch Test Group, J. Am. Acad. Dermatol., 25, 59-68, 1991. 

At present, contrary to other dermatological diagnostic techniques, such as the photopatch test or photoprovocation testing, there are neither standardized test protocols nor established sourees of light or test substances available for FDAP, so that there is still a high demand for more research. 

The best method for demonstrating photoallergy is the photopatch test, which must be carried out with special care and the use of a light source rich in ultraviolet... 

Photosensitivity reactions are diagnosed with increasing frequency because dermatologists are alerted to morphology, anatomic distribution, and photopatch testing methods. 

The halogenated salicylanilides (tetrachlorosalicylanilide, brominated salicylanilides) and related compounds caused an epidemic of adverse reactions to sunlight between 1960 and 1970, when they were incorporated as antibacterials in soaps and cosmetics (Wilkinson 1961 Calnan et al. 1961 Epstein et al. 1968). After 1968 a striking reduction in numbers of patients with positive photopatch tests to these compounds has been noted (Smith and Epstein 1977), and explained partly by removal from the market of the more potent photosensitizing chemicals, partly by increased awareness by physicians. 

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