[Phototoxic and photoallergic reactions]. / Phototoxische und photoallergische reaktionen.

Many artificial or naturally occurring substances are included under the term photosensitizer. After ultraviolet (UV) exposure such agents can lead to increased photosensitivity and subsequently to phototoxic or photoallergic reactions in the skin. From clinical observations and comprehensive studies typical reaction patterns can be deduced which can clarify the difference between phototoxic and photoallergic dermatitis.An illuminated epicutaneous test based on conventional epicutaneous tests, the photopatch test, was developed as a screening method for identification of photosensitizers. The diagnostic specificity and sensitivity of the test is comparable to conventional epicutaneous testing. If possible photosensitizers do not cause any relevant reactions with the photopatch test, other test procedures, such as the photoprick, photoscratch and illuminated intracutaneous tests are available. If the actual photosensitizer is not the test substance but a metabolite of the test substance, a systemic photoprovocation test can be indicated.

Dioxopromethazine-induced photoallergic contact dermatitis followed by persistent light reaction.

BACKGROUND: Although photosensitivity after photoallergy to topical phenothiazine antihistamines is well known, there have been no previous reports of dioxopromethazine inducing this phenomenon. OBJECTIVE: A housewife used 0.5% dioxopromethazine in Prothanon gel for palpebral pruritus and developed severe dermatitis of the lower eyelids with spread to the sun-exposed areas. METHODS: The minimal erythema doses and the minimal infiltrate doses for ultraviolet A (UVA) and ultraviolet B (UVB) were established before photopatch testing and at intervals up to 497 days thereafter. Test sites were read up to 144 hours after irradiation. Photopatch testing was performed with Prothanon gel, dioxopromethazine hydrochloride 0.001% to 0.5%, and the standard photopatch test tray (Hermal/Trolab). For patch testing, various series of the German Contact Dermatitis Group were applied. RESULTS: Minimal erythema doses for UVA were diminished before photopatch testing and at intervals up to 500 days after Prothanon gel was discontinued. Exposure to UVB provoked abnormal delayed infiltrated reactions. Clinically the photosensitivity persisted within this period. Photoallergic reactions were seen with Prothanon gel, dioxopromethazine hydrochloride 0.005% to 1.0%, and promethazine hydrochloride 0.1%. The patient gave positive patch test reactions to various fragrance materials, balsam of Peru, costus oil, and propylene glycol. CONCLUSION: Because topical dioxopromethazine may cause photoallergic contact dermatitis followed by long-lasting photosensitivity even after contact has been discontinued, its withdrawal from the market is recommended.

[Effect of coal tar on cignolin erythema--1 hour treatment of psoriasis with high-dose cignolin with and without tar]. / Einfluss von Steinkohlenteer auf das Cignolinerythem-die hochdosierte Cignolin-Einstundentherapie der Psoriasis mit und ohne Teerzusatz.

Coal tar applied simultaneously showed a suppressive effect on anthralin erythema. This effect was demonstrated by an epicutaneous test 24 hours (27 patients) and 1 hour (46 patients) after application of various concentrations of anthralin combined with tar 3%. In a clinical study on 9 patients, anthralin 3% alone or combined with tar 10% were administered in a right and left comparison on symmetrical chronic psoriatic lesions for 1 hour daily. Anthralin plus tar exhibited a stronger anti-psoriatic effect than anthralin alone did. Tar reduced the anthralin erythema in the perilesional skin. These findings favor the combination of coal tar and anthralin in the 1-hour treatment schedule of psoriasis.

[Retinoid therapy and phototherapy of psoriasis (author's transl)]. / Retinoid- und Phototherapie der Psoriasis.

26 patients with generalized psoriasis were treated with oral Retinoid (Ro 10-9359; 50-150 mg/day) and radiations (2-5 times per week) with two different light sources emitting UVA and UVB. In 22 patients, remission was seen with only few remaining lesions at the predilection sites within 35 days. There was no obvious difference in the effect of the two light sources. 17 patients remained free from lesions for several months under a low-dose treatment with Ro 10-9359 and 2-8 radiations per month. The side effects of this treatment were negligible. This therapy is especially suited for outdoor patients with generalized psoriasis.

Influence of a systemically administered aromatic retinoid (Ro 10-9359) on the light sensitivity.

The light sensitivity was determined on 14 psoriasis patients using two different light sources before, and after a three week period of systemic administration of 75 to 100 mg daily of the aromatic retinoid (ethyl ester of all-trans-9-(4-methoxy-2,3,6-trimethylphenyl)-3,7-dimethyl-2,4,6,8-nonatetraenoic acid, Ro 10-9359 [1]). The results indicate that with this therapy, the light sensitivity remains unchanged or even decreases; there is thus no contraindication to the simultaneous application of phototherapy and the systemic administration of this retinoic acid derivative.