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Electron Microscopy of Argyria Treated With Picosecond Alexandrite Laser
摘要： Argyria (from the Greek word for silver, argyros) is the bluish gray discoloration of tissue caused by exposure to silver or its salts, often because of alternative medicine treatment or occasionally through occupational exposure. Since the 1990s, colloidal silver has been available in pharmacy-supplied dietary supplements and homeopathic remedies for the treatment of various diseases, including cancer, immunodeficiency, chronic fatigue, tuberculosis, and other infections, without any substantiating evidence. Long-term consumption of silver products can lead to chronic argyria, with silver deposition in organs, including the skin, liver, spleen, kidneys, and central and peripheral nervous system. Generalized argyria can occur when silver compounds are ingested, applied topically, or inhaled. Argyria can also be localized to certain sites of the skin or eyes if creams or eye drops are used or can be found on the ear lobes when silver earrings are worn. Silver deposits may localize in the eccrine glands of the skin, as well as in the papillary dermis and pilosebaceous follicles. The silver is in the form of silver sulfide and appears to be more abundant in the sun-exposed skin. Argyria has a well-defined toxicity, and discoloration is permanent. Recently, Q-switched nanosecond laser and picosecond alexandrite laser (PicoSure, Cynosure) have been used to treat argyria. Both the Q-switched nanosecond laser and the picosecond alexandrite laser use the principle of selective photothermolysis and have been used in a number of applications, including tattoo removal and pigmentation removal. Pulses of light energy is delivered to the skin and causes fragmentation of ink particles, allowing for phagocytosis and removal of the pigment by macrophages. It is speculated that laser treatment of argyria causes fragmentation of silver deposits in the skin, similar to the mechanisms of tattoo removal. We present a case report of the successful treatment of argyria with picosecond alexandrite laser, as demonstrated by clinical photographs, histopathology, and electron microscopy. This case provides evidence that picosecond laser causes the fragmentation of silver particles in argyria without phagocytosis in the immediate post-treatment phase.
关键词： picosecond alexandrite laser,silver particles,argyria,laser treatment,electron microscopy
更新于2025-09-12 10:27:22
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Q-Switched Alexandrite Laser and Topical 20% Monobenzyl Ester of Hydroquinone Removal of Tacrolimus-Induced Repigmentation (After Complete Depigmentation With 20% Monobenzyl Ether of Hydroquinone)
摘要： Monobenzyl ester of hydroquinone (MBEH) has been used as a bleaching agent in patients with widespread vitiligo. The depigmentation from bleaching agents is not permanent, and pigmentation has been reported to spontaneously recur. We report a case of repigmentation in a completely depigmented patient who was using topical tacrolimus. A 63-year-old fair-skinned Indian woman presented to our clinic with multiple irregular dark brown macules on her cheeks, ears, and periorbital region. She developed vitiligo in her early 20s, and because of its extensive nature, she elected to undergo treatment with topical 20% MBEH in 1989. Within 1 year, she achieved total body depigmentation. Twenty-two years after her treatment with MBEH, she developed eyelid dermatitis for which she was prescribed topical tacrolimus 0.03% ointment. Over several weeks, she developed dark brown pigmentation in all areas treated with tacrolimus. She presented to our clinic for treatment of the pigmented areas, which she noted was identical to her natural dark brown skin tone. The tacrolimus was discontinued, and she was initially treated with 755-nm Q-switched (QS) alexandrite laser (8–8.5 J/cm2, 3 mm, 50 ns) at monthly intervals. Notably, with her recent history of eyelid dermatitis, topical MBEH was not chosen because of the initial treatment due to its known adverse effect of irritant dermatitis. After each treatment with the QS alexandrite, she had partial resolution, but in the subsequent 2 to 3 weeks, the pigmentation returned. After 2 treatments with the QS alexandrite alone and no recurrence in eyelid dermatitis, compounded topical 20% MBEH (Park Pharmacy, Irvine, CA) was added to her regimen to apply daily to the pigmented areas. After 3 additional laser treatments with concomitant topical therapy, the pigmentation resolved completely. These results have been maintained for 3 months after the last treatment.
关键词： MBEH,tacrolimus,vitiligo,repigmentation,Q-switched alexandrite laser
更新于2025-09-12 10:27:22