Abstract

Toxic Melanoderma/Riehl’melanosis is a facial melanosis attributable to phototoxic reaction to skin contact with photoactive agents. Suspected cause could be tar derivatives, fragrances, cosmetics ingredients and drugs. It is characterized by reticulate pigmentation, typically presents as a gray-brown to black hyperpigmentation on the face and neck, may extend to the chest, scalp, and occasionally involves the hands and forearms. We successfully treated a case of Riehl’ melanosis with Q switched Nd: YAG1064nm laser, which was recalcitrant to various systemic and topical treatments. Earlier studies have been found notable clinical improvements in the treatment of this condition for Intense Pulsed Light (IPL) and low-pulse energy 1,064-nm Q-switched (QS) Nd:YAG laser.We observed that Riehl's melanosis was effectively and safely treated with a low-pulse energy 1,064-nm QS Nd:YAG laser, especially in Indian population where there is chance of post inflammatory hyperpigmentation from excessive light or laser energy devices.

We report a case of 35 year female presented with bluish-grey pigmentation over face, neck, anterior chest arm and forearm for six months duration.There was preceding history of erythema and pruritus with subsequent interval hyperpigmentation developed over the skin lesions. There was no prior history of any drug intake,photosensitivity,trauma. She had a history of henna application for ten year duration. Skin biopsy showed unremarkable epidermis, papillary dermis shows mild perivascular mononuclear cell infiltrate,melanin incontinence and few melanophages. She received various treatment in the form of dapsone, topical tacrolimus,hydroquinone and retinoid with mometasone mixed cream.Chemical peel with retinoic acid was done for 10-12 sittings with minimal improvement. Laser toning with Q switched Nd: YAG1064nm was given at 4 weeks interval at 2-3j/cm2 spot size 6-8mm. Total 6 sittings were done with significant reduction of her pigmentation.