Histologic comparison of argon and tunable dye lasers in the treatment of tattoos.

Cosmetic benefit from laser therapy of tattoos may simply be the result of thermal injury and host reparative response which remove pigment by a "slough and bury" mechanism. Tattoo pigment of 4 colors (black, white, red, and blue) was introduced into the skin of guinea pigs and studied histologically at 48 h, 7 days, 4 and 6 weeks, and 3 months. Tattoos of each color were treated with argon laser (488 and 514 nm) and tunable dye laser at 3 different wavelengths (505, 577, and 690 nm).

Coal tar phototoxicity: characteristics of the smarting reaction.

We examined the properties and ultraviolet exposure parameters of tar smarts in an effort to elucidate the mechanisms involved. We showed that irradiation with 1 minimal smarting dose (MSD) of UVA immediately following tar removal lowered the MSD for 6 h, demonstrated by subsequent challenge with UVA. Following 3 MSDs this "memory" effect was demonstrable for 24 h.

Psoralens and UV-A and UV-B twice weekly for the treatment of psoriasis.

In an effort to determine if combination phototherapy (psoralens and UV-A [PUVA]) [PUVA-UV-B]) administered twice weekly provides a substantial advantage over therapy with PUVA alone, we investigated twice-weekly PUVA-UV-B therapy for the treatment of psoriasis. In a bilateral comparison study of 11 patients, we found that seven cases of psoriasis cleared in the same number of treatments with PUVA-UV-B or PUVA, but in four cases the PUVA-UV-B treated side cleared significantly more rapidly. In a study of these 11 split cases, plus ten additional patients treated with PUVA-UV-B twice weekly, this therapy was effective in clearing psoriasis.

Role of ultraviolet A in phototherapy for psoriasis.

Multiple studies have demonstrated that the doses of ultraviolet A (UVA) (320-400 nm) achieved with ultraviolet sources presently used for phototherapy for psoriasis are inadequate to induce coal tar phototoxicity (as manifested by delayed erythema). Some centers still use a phototherapy protocol that combines UVA, ultraviolet B (UVB), and tar for the treatment of generalized psoriasis. We designed a bilateral comparison study to determine whether the addition of UVA to one side, in doses sufficient to induce an immediate burning or smarting sensation in tar-treated skin, would add to the beneficial effects of UVB.

Malignant lymphoma presenting with cutaneous granulomas.

A 49-year-old man with fever, malaise, weight loss, and pneumonia developed cutaneous nodules and neurologic symptoms. Skin biopsy studies revealed granulomatous inflammation consistent with a sarcoid reaction, and mild granulomatous changes were noted on biopsy specimens of liver and bone marrow. A lymph node biopsy was unremarkable.

Coal tar phototoxicity: kinetics and exposure parameters.

We examined two manifestations of coal tar phototoxicity: delayed erythema and skin pain (tar smarts) by quantifying the amount (dose) of UVA and exposure conditions required to induce these phenomena in normal human skin. The minimal UVA dose required to induce delayed erythema (minimal phototoxic dose or MPD) and the minimal UVA dose required to induce an immediate smarting reaction (minimal smarting dose or MSD) were recorded in 32 subjects in a variety of settings. A log-log dose-response model described the relation between the interval of time tar was left on the skin and lowering of MPD.