Photopatch Testing Research Articles

Occupational Contact Dermatitis to Thiourea and Dimethylthiourea From Diazo Copy Paper

A 44-year-old construction designer developed acute dermatitis on his palms, dorsal side of hands, face and neck. According to the patient, the lesions were caused by the occupational daily contact with diazo copy paper. It contained thiourea and dimethylthiourea as antioxidants. Patch tests proved sensitization to diazo copy paper—exposed and unexposed—thiourea, dimethylthiourea, and to the ammonia salts used as developers. Thioureas reactions were intensified after the standard irradiation for photo-patch testing. Considering that thioureas and derivatives are used in almost all kinds of diazo photocopy paper, the authors believe that thiourea allergy from this source has virtually been overlooked.

Occupational Contact Dermatitis to Thiourea and Dimethylthiourea From Diazo Copy Paper

A 44-year-old construction designer developed acute dermatitis on his palms, dorsal side of hands, face and neck. According to the patient, the lesions were caused by the occupational daily contact with diazo copy paper. It contained thiourea and dimethylthiourea as antioxidants. Patch tests proved sensitization to diazo copy paper—exposed and unexposed—thiourea, dimethylthiourea, and to the ammonia salts used as developers. Thioureas reactions were intensified after the standard irradiation for photo-patch testing. Considering that thioureas and derivatives are used in almost all kinds of diazo photocopy paper, the authors believe that thiourea allergy from this source has virtually been overlooked.

Photosensitization caused by ibuprofen

Several nonsteroid antiinflammatory drugs (e.g., benoxaprofen, carprofen, and piroxicam) are known to induce photosensitivity reactions, but this has not yet been documented for ibuprofen. We observed a photosensitivity reaction in a patient treated with an oral ibuprofen preparation. This patient had a lowered minimal erythema dose for UVA but not for UVB after oral administration of ibuprofen. Results of a photopatch test with the drug were negative. In vitro UVA irradiation of human erythrocytes in the presence of ibuprofen caused ultraviolet dose-dependent phototoxic hemolysis.

Allergic photocontact dermatitis due to suprofen

We report 5 cases of photocontact dermatitis due to suprofen, a nonsteroidal anti-inflammatory drug introduced to the Japanese market in 1989, and available as a 1% ointment. The patients developed pruritic eczematous lesions after applying the ointment for from 2 weeks to 3 months. All 5 patients reacted positively to photopatch testing with ultraviolet A (UVA) and suprofen down to 0.1-0.01% pet., and 3 patients showed positive reactions with ultraviolet B (UVB) and suprofen down to 1.0-0.1%. Moreover, all patients showed a cross-reaction with tiaprofenic acid, which has a very similar chemical structure to suprofen. However, there was no cross-reaction between suprofen and ketoprofen. Prescribers should be aware of the existence of photocontact sensitivity due to these drugs.

A three-year photopatch study in Thailand

Photopatch testing was performed on 274 patients who had history of photosensitivity at the Institute of Dermatology Thailand from 1987 through 1989. A total of 92 positive photocontact reactions and 71 positive contact reactions were seen. The most frequent positive photopatch test reactions were to sulfanilamide (18.2%) followed by Jadit (4.4%) chlorpromazine (3.6%) promethazine (3.6%) and fenticlor (3.2%). The most common photodermatoses was polymorphous light eruption (60.9%). Photocontact dermatitis was established in 28 patients (10.2%) while other skin diseases aggravated by sunlight were seen in 47 patients (17.2%).

Photopatch testing: The 5-year experience of the German, Austrian, and Swiss Photopatch Test Group

A cooperative photopatch test study was conducted by 45 dermatologic centers in Austria, Germany, and Switzerland. Results obtained from 1985 to 1990 are presented. A standard photopatch test tray of 32 substances was applied to the back of patients with suspected photosensivity. After applications for 24 hours, test sites were irradiated with 10 joules/cm2UVA. Unirradiated controls were included. Readings were performed immediately and 24, 48, and 72 hours after irradiation; responses were qualitatively graded on a 4-point scale. All data were stored and processed by a computer. With computer-assisted analysis of reaction patterns photoallergic reactions were identified and distinguished from phototoxic reactions. Data of 1129 patients were evaluated. Among a total of 2859 positive test reactions in 870 patients, 2041 in 778 patients were found to be photoinduced and 818 in 413 patients were contact reactions; 108 reactions in 83 patients were classified as photoallergic. Nonsteroidal anti-inflammatory drugs, disinfectants, sunscreens, phenothiazines, and fragrances caused most often photoallergic reactions. Many unspecific phototoxic reactions were induced by tiaprofenic acid, promethazine, carprofen, chlorpromazine, fenticolar, wood balsam of Peru, and perfumes. Despite the distinction between photoallergic and phototoxic responses, many test reactions lacked relevance for the patients' dermatoses.

Cross‐reactivity between sensitivity to thimerosal and photosensitivity to piroxicam in guinea pigs

Piroxicam (PXM) is a nonsteroidal anti-inflammatory drug which may induce a photosensitive eruption shortly after administration. We examined whether animals sensitized to thimerosal developed a photosensitivity to PXM. Male Hartley strain guinea pigs were sensitized to thimerosal, thiosalicylate and PXM separately. The open patch test was used to evaluate sensitization to each drug and cross-reactions between the drugs. Animals sensitized to thimerosal exhibited positive patch test reactions to thiosalicylate and positive photopatch test reactions to PXM. Both those sensitized to thiosalicylate and to PXM showed positive patch test reactions to PXM. This study demonstrated that thimerosal induces cross-sensitivity to PXM in vivo and that the common active component among these compounds may be thiosalicylate.

A case of photosensitivity and contact allergy to systemic tricyclic drugs, with unusual features

A 43-year-old farmer on tricyclic antidepressive drugs developed a severe photodermatitis with associated liver involvement. The lesions spread to covered areas of the skin, suggesting photoallergy clinically. Patch and photopatch testing revealed photoallergy and contact allergy to clomipramine and contact allergy also to carbamazepine. In addition, the patient had positive patch test reactions to chlorpromazine, balsam of Peru and fragrance-mix, as well as a positive photopatch test to fentichlor. UVA and UVB erythema thresholds were normal. In this patient, an initial episode of photosensitization, probably elicited by clomipramine, was accompanied by contact allergy to this drug and to carbamazepine. The contact sensitivity to clomipramine could also be elicited by oral provocation without UV light. Hypothetically, a photoproduct of clomipramine may have been the original sensitizer, this compound subsequently cross-reacting with clomipramine and, possibly with carbamazepine.

Sensitivity to thimerosal and photosensitivity to piroxicam

17 patients allergic to thimerosal, with no previous history of photosensitivity or piroxicam ingestion, 2 patients with piroxicam-induced photosensitivity, and 10 controls were patch or photopatch tested, with 1 or more of the following: thimerosal, thiosalicylic acid, irradiated and non-irradiated solutions of piroxicam alone, L-cysteine alone and piroxicam plus L-cysteine, and piroxicam in petrolatum., The results of the tests supported the hypothesis that there are cross-reactions between thiosalicylic acid and prioxicam, a photosensitizer. The mechanism of the cross-reactions may involve photoproducts of piroxicam and L-cysteine, as patients allergic to thiosalicylic acid, who have positive photopatch tests to piroxicam, also had positive patch tests to the irradiated solution of piroxicam plus L-cysteine.

Contact Dermatitis Caused by Topical Minoxidil: Case Reports and Review of the Literature

Sixty-seven patients using a minoxidil solution for the treatment of hair loss developed a contact dermatitis of the scalp. Patch tests showed a positive reaction to topical minoxidil in 25 patients, one of whom also presented a positive reaction to propylene glycol. A positive photopatch test to topical minoxidil was detected in two patients who had a negative patch test to the drug. Minoxidil allergic contact dermatitis was frequently observed in patients who had been using topical minoxidil for a long period of time. Patch test results from our clinic suggest that minoxidil is one of the most frequent sensitizers among topical drugs. Patch tests and photopatch tests with topical minoxidil should possibly be performed in every patient who experiences local side effects after application of minoxidil solutions. Because patients with irritative dermatitis can usually tolerate topical minoxidil continuing the treatment, identifying the subjects that are sensitized to the drug is essential for patient counseling.

Persistent light reaction to hexachlorophene

The first patient with what appears to be persistent light reaction caused by hexachlorophene alone is reported. Persistent light reaction may occur in patients with milder degrees of photosensitivity, and appropriate photopatch testing should be performed.

A case of piroxicam-induced photosensitive dermatitis

We report a case of piroxicam-induced photosensitive dermatitis in a 54-year-old female. She had taken oral piroxicam and was exposed to the sunlight on her way home for a few minutes. Several hours after the sun-exposure she developed well-defined, confluent, erythematous plaques and numerous vesicobullae with pruritus and prickling sensation on the sun-exposed areas. A phototest was done on her first visit. The minimal erythemogenic dose(2J/) of ultraviolet(UV) A was markedly decreased whereas that of UVB was within a normal limit. Visible light irradiation for 30 minutes did not cause skin lesions. Six months after the initial skin lesions, a photopatch test with 1% and 10% piroxicam solution followed by UVA(10J/) irradiation showed positive responses on both concentrations.

Allergic contact and photocontact dermatitis due to psoralens in patients with psoriasis treated with topical PUVA

The incidence and clinical features of allergic contact and/or photocontact dermatitis due to psoralens were examined in 371 patients with psoriasis treated with topical PUVA. The psoralen derivatives used in the study were 8-methoxypsoralen (8MOP), 3-carbethoxypsoralen (3CPs), 4,6,4'-trimethylangelicin (TMA) and 7-methyl pyridopsoralen (MPP). Of 371 patients treated with 8MOP, three (0.8%) developed an acute dermatitis in the PUVA-treated areas. This incidence was significantly lower (P less than 0.01) than that for 3CPs (four of 10 patients) or that for TMA (six of 17 patients). None of the seven patients receiving MPP on PUVA had a reaction. It was confirmed that these dermatitis reactions were due to contact and/or photocontact allergy to psoralens by several methods that include patch and photopatch tests, photopatch test mapping, determination of the minimal erythema dose (MED) and immunohistochemistry.

Sunscreen Allergy

The results of patch and photopatch tests in a series of 14 Australian patients with suspected sunscreen allergy are presented and the international literature on sunscreen allergy is reviewed. There were a total of 14 allergic reactions to sunscreen chemicals observed in 10 patients over 7 years (1982 to 89). There were six positive photopatch reactions to PABA, four to benzophenone, three to butyl methoxy dibenzoylmethane, and one to cinnamate. Three patients had positive tests to more than one of these chemicals. In two more patients reactions were caused by an allergy to a component of the sunscreen base, and in another two patients to an irritant reaction caused by simultaneous use of a moisturizing cream. Not only PABA-related chemicals, but all the other active sunscreen agents commonly used in Australian sunscreen products (cinnamates, benzophenones, and dibenzoylmethanes) are potential allergens. Informed advice on future skin protection requires identification of the allergen with patch and photopatch testing.

Contact and photocontact allergy to ketoprofen: clinical and experimental study

In the last 3 years, we have studied 10 patients with allergic reactions to topical ketoprofen. We have investigated the sensitization and irritant potential of the drug and the possibility of cross-reactivity with other aryl-propionic non-steroidal anti-inflammatory drugs (ibuproxam, ibuprofen, naproxen, fenoprofen, flubiprofen and tiaprofenic acid). 2 of our patients had contact dermatitis, and the other 8 photocontact dermatitis. One of our patients showed cross-reactivity between ketoprofen and ibuproxam on patch testing. In the photopatch tests, we observed cross-reactivity between ketoprofen and tiaprofenic acid in 2 patients, and cross-reaction between ketoprofen and ibuproxam and flurbiprofen in another case. Experimental studies, including human maximization and photomaximization tests, performed in 20 healthy volunteers, showed a complete absence of sensitization, 3 volunteers showed a marked irritant reaction to ketoprofen (20% pet.) during either maximization (2 cases) or photomaximization (1 case) tests. Although ketoprofen appears not to be a sensitizing agent in human volunteers, the fact that photosensitization to this drug seems to be quite common after topical use suggests that there are some local or individual factors, at present unknown, facilitating the development of allergy.

Piroxicam-induced photosensitivity and contact sensitivity to thiosalicylic acid

A photocontact dermatitis developed in three patients after the application of gel containing 0.5% piroxicam. Patch tests were positive to thiomersal and thiosalicylic acid. Photopatch tests with piroxicam at several concentrations were positive in the three patients but negative in 62 normal volunteer subjects. Patch tests performed on 14 patients with proved systemic photosensitivity to piroxicam were positive for thiomersal and thiosalicylic acid. Nine of 12 patients previously sensitized to thiosalicylic acid and with no history of exposure to piroxicam showed positive photopatch test reactions to this chemical. These results support a relation between piroxicam-induced photosensitivity and contact sensitivity to thiosalicylic acid. Contact allergic sensitivity to the latter is a marker for patients with a high risk of developing photosensitivity reactions to piroxicam. These reactions may be due to photoproducts of the drug rather than metabolites.

Photosensitivity in the elderly

Photosensitivity to drugs and chemicals in the elderly is more prevalent due to more frequent use of medications. Phototoxic reactions to common, orally administered drugs such as diuretics, cardiac agents and antidiabetics may occur and the reactions may be remedied by discontinuing drug therapy. Photocontact dermatitis due to the ingredients in sunscreens or other agents, such as perfumes, may also arise. Diagnosis is often confirmed by photopatch testing and subsequent avoidance of these agents leads to gradual resolution. Idiopathic photodermatoses, such as sunlight-induced polymorphic light eruption or solar urticaria, may occur and persist from an early age and, in elderly subjects, they can cause mild to marked disability. The most disturbing disorder of this type is the severe, widespread eczematous chronic actinic dermatitis, which can be difficult to diagnose. Porphyrias, such as variegate porphyria or erythropoietic protoporphyria, may persist from an early age, whereas porphyria cutanea tarda generally begins in later life. Porphyrias all have specific clinical and biochemical features and, apart from variegate porphyria, usually respond well to treatment following diagnosis. Exposure of elderly skin to sunlight may also cause deterioration of many ordinary dermatoses, particularly seborrhoeic eczema, which generally respond to protection from UV exposure and to treatment of the underlying abnormality. Progress in identifying the underlying causes, the availability of increasingly sophisticated diagnostic techniques, and improvements in sunscreen preparations and therapeutic medications will probably significantly reduce abnormal photosensitivity in the elderly in the near future.

Contact allergy to Compositae plants in patients with summer‐exacerbated dermatitis

16 patients with summer-exacerbated dermatitis were examined by patch testing and photopatch testing with a battery of Compositae and standard allergens. IgE and RAST, and the thresholds to UVA and UVB, were determined. 6 female and 2 male patients showed allergic contact reactions to one or more Compositae extracts from flowers common in Sweden, also used in skin care products. The study points to the importance of including testing with Compositae allergens in patients with summer-exacerbated dermatitis. This group comprises patients with multiple contact reactions, photosensitivity and flares of atopic dermatitis.

Photoallergic reaction to fluorescein

A photoallergic reaction to fluorescein was demonstrated in a male diabetic by photopatch and photoprovocation tests. Sensitization was acquired by tonometries using a fluorescein-containing local anesthetic, preceding fluorescein angiography for diagnosis of diabetic retinopathy. Histopathological examination of skin lesions induced in both photopatch and photoprovocation tests confirmed the diagnosis of photoallergic reaction to fluorescein.

The Cutaneous Effects of the Common Concretes and Absolutes Used in the Perfume Industry

ABSTRACT The cutaneous reactions of commercially available absolutes, concretes and extracts used as raw materials in the fragrance industry were examined in detail. Using epicutaneous and photo patch tests on undiluted products, the concentration at which the irritant activity and phototoxicity was no longer observed was determined for 42 different raw materials. Further-more, the allergic reaction to the test substances by subjects previously sensitized by Peru balsam oil and/or perfumes and other fragrance materials also was determined. It was found that extracts that should be used at restricted concentrations because of their phototoxic or irritant activity were the absolutes of Aleppo pine needle, juniper, Kuberose laurel leaf, nutmeg, tarragon (estragon), rae, clove bud, jasmin, sage, lavender, lavandin, thyme, immortelle and wild chamomile.