Treatment of pseudofolliculitis barbae in very dark skin with a long pulse Nd:YAG laser.

BACKGROUND: Pseudofolliculitis barbae affects some individuals with coarse curly hair. Currently available treatment modalities are often ineffective. In some studies, lasers have been shown to be potentially helpful in mitigating disease severity by reducing the number and/or thickness of hair shafts. METHODS: This was a side-by-side interventional study conducted at a military tertiary medical facility. The study group included 26 patients (skin types IV, V, and VI) referred from primary care physicians with a diagnosis of pseudofolliculitis barbae refractory to medical therapy. A neodymium YAG laser was used to treat one half of the neck. One month later, shaving bumps were counted and compared to their preoperative levels on both sides. RESULTS: Mean postoperative papule counts were 11.6 +/- 6 (SD) and 30.1 +/- 19 (SD) on the treated side and untreated sides, respectively. CONCLUSION: Neodymium YAG laser treatment represents a safe and effective option for reducing papule formation in patients with pseudofolliculitis barbae.

Acne treatment with a 1,450 nm wavelength laser and cryogen spray cooling.

BACKGROUND AND OBJECTIVES: A laser with a wavelength in the mid-IR range targeting the depth in skin where sebaceous glands are located in combination with cryogen spray cooling was evaluated for treatment of acne. In this non-ablative treatment, the laser energy heats the dermal volume encompassing sebaceous glands whereas the cold cryogen spray preserves the epidermis from thermal damage. STUDY DESIGN/MATERIALS AND METHODS: Monte Carlo simulations and heat transfer calculations were performed to optimize the heating and cooling parameters. A variety of heating and cooling parameters were tested in an in vivo rabbit ear study to evaluate the histological effect of the device on sebaceous glands and skin. Similar experiments were performed on ex vivo human skin. A clinical study for the treatment of acne on backs of human males was also conducted. RESULTS: Monte Carlo simulations and heat transfer calculations resulted in a thermal damage profile that showed epidermal preservation and peak damage in the upper dermis where sebaceous glands are located. Ex vivo human skin histology confirmed the damage profile qualitatively. In vivo rabbit ear histology studies indicated short-term thermal alteration of sebaceous glands with epidermal preservation. In the human clinical study on the back, a statistically significant reduction in lesion count on the treated side compared to the control side was seen (p < 0.001). Side effects were transient and few. CONCLUSIONS: The studies reported here demonstrate the feasibility of treating acne using a photothermal approach with a mid-IR laser and cryogen cooling.