Wireless over‐ear headphones: A new source of allergic contact dermatitis to isothiazolinones

Abstract

Psoralen-containing plants have a significant role in the treatment of vitiligo in both traditional and modern medicine systems.There are many modern medicines that contain psoralens isolated from plants (rather than artificially synthesised psoralens), which are administered in regulated protocols for photochemotherapy using artificial UV-A light (PUVA) or sunlight as the source of UV-A (PUVAsol). Even therapies developed from traditional systems also mention titration of dose and duration of sun exposure, and gradual increase, similar to PUVAsol therapy in modern medicine. But such traditional preparations are often used unsupervised by the patients. They often use excessive dose of the active component or excessive sun exposure without subsequent photoprotection, often intentionally in hopes of getting faster pigmentation, or inadvertently due to unregulated preparations leading to severe adverse effects. The topical formulations can lead to very high concentration of the drug in the skin, which can be more injurious and have lower thresholds of sun exposure to produce phototoxic reactions. 4 Frequently, after resolution of acute dermatitis, there might be development of slight hyperpigmentation over the exposed normal skin and some repigmentation over the vitiligo patches. It is suggested that the perifollicular melanocytes undergo significant damage during the acute dermatitis episodes, limiting the response to future phototherapy interventions. [4][5][6] Mild hypopigmented scarring, as seen in our patient, can also occur, which also limits future response.In conclusion, severe phytophototoxic reactions to psoralen-containing plants taken for treatment for vitiligo can present as thermal burns. When introduced to such therapies, patients must be sensitised about the potential adverse effects of overdose or overexposure and the need for complete photoprotection apart from the strictly titrated duration of sun exposure similar to PUVAsol therapy.