A non-sterile, topically-applied gel/suspension intended to be used in conjunction with a lamp/laser to treat an inflammatory skin disorder (e.g., rosacea, psoriasis, acne) as part of photothermal therapy (PTT). It contains micro-/nano-particles intended to be delivered to a dermal structure (e.g., sebaceous glands, hair follicles), whereby absorption of light causes them to heat up (photothermal heating) to produce a therapeutic effect. It is intended to be used by a healthcare professional in a clinical setting. After application, this device cannot be reused.