Photodermatitis from topical phenothiazines: A case series

Abstract

In Europe, contact photosensitivity to phenothiazines is known particularly in southern countries. Topical phenothiazines are widely used and sold over-the-counter for the treatment of mosquito bites and pruritus in France. Objective:To report a series of cases with photodermatitis to topical phenothiazines. Method:A retrospective study of cases of contact dermatitis to phenothiazines seen in French photodermatology centres was performed. Results:In all, 14 patients with the diagnosis of contact dermatitis to phenothiazines were included. These developed eczema on the application sites, and in 13 the eruption spread to photodistributed sites. Topical products containing isothipendyl were the most common cause of photodermatitis. One patient had photoaggravated eczema due to promethazine cream. All patients stopped using topical phenothiazines and were treated successfully with topical corticosteroids. One patient relapsed and developed persistent light eruption. In all of the 9 cases tested, photopatch testing to the topical phenothiazine used "as is" was positive.Isothipendyl, chlorproethazine and the excipients were not tested. Photopatch tests to chlorpromazine and promethazine were positive in 8/12 and 7/13 tested respectively. Conclusion:Use of isothipendyl and promethazine as over-the-counter (or even prescribed) drugs needs to be limited due to severe reactions and sensitization to other phenothiazines that otherwise will have to be avoided.

Photopatch testing in Chinese patients: A 5‐year experience

“…14,15 A recent study reported a series of cases of PACD caused by topical phenothiazines, widely used as over-thecounter (OTC) antipruritic drugs in France. 16 Chlorpromazine, which is a phenothiazine, led to PACD in the greatest number of patients, with 23.8% of the patients recruited reporting positive PACD reactions, but only 13.0% of those reactions were of current or past relevance. Analysis of clinical relevance (13%) showed that only seven patients were health-care workers or pharmaceutical workers who handled phenothiazines for occupational needs, while most of the patients used drugs containing phenothiazines (especially promethazine).…”

“…Phenothiazines are known as a class of organic compounds that are considered to be representative drugs for inducing phototoxic reactions as well as PACD 14,15 . A recent study reported a series of cases of PACD caused by topical phenothiazines, widely used as over‐the‐counter (OTC) antipruritic drugs in France 16 . Chlorpromazine, which is a phenothiazine, led to PACD in the greatest number of patients, with 23.8% of the patients recruited reporting positive PACD reactions, but only 13.0% of those reactions were of current or past relevance.…”

Perioral photoallergic dermatitis to promazine hydrochloride

“…Topical phenothiazine antihistamine preparations are well-known strong contact and photocontact sensitizers and therefore they have been withdrawn in many countries. 1,5 Our patient developed dermatitis after a 6-month administration of promazine oral drops. Because of the patient's difficulties in swallowing, the oral drug spilled onto the skin surrounding her mouth and possibly acted as a photocontact allergen.…”

“…These old heterocyclic drugs are well‐known phototoxic compounds, but they can also induce allergic and photoallergic dermatitis. Topical phenothiazine antihistamine preparations are well‐known strong contact and photocontact sensitizers and therefore they have been withdrawn in many countries 1,5 …”

“…Phenothiazines are well‐known inducers of contact and photocontact sensitivity when utilized as topical antihistamines, 1,2 while phototoxic reactions induced by their systemic use as antipsychotic drugs are rarely reported 3,4 . Among phenothiazines, promazine hydrochloride is widely used and rarely described as photosensitizer 5 .…”