Photodynamic therapy is a new therapeutic technology emerging in recent years, which uses specific wavelength laser to irradiate the diseased tissues that have absorbed photosensitizers, causing them to undergo a photochemical reaction, generating free radicals, singlet oxygen, and other toxic substances, and inducing apoptosis and necrosis of the cells, so as to achieve the therapeutic purpose. Indications: 1, Acne: moderate to severe acne especially cystic acne, nodular acne and all kinds of intractable acne. 2, Condyloma acuminatum: (especially recurrent condyloma acuminatum), flat warts, common warts, etc. 3, skin tumors: basal cell carcinoma, Bowen’s disease, squamous cell carcinoma, paget’s disease (eczema-like carcinoma), etc. 4, pre-cancerous lesions: actinic keratosis, value-added erythema, leukoplakia of mucous membranes, Bowen’s papulopapulosis, etc. Treatment Advantages: 1, low recurrence rate can remove latent foci, sub-clinical infections, so as to reduce the rate of recurrence. Low recurrence rate 2, very small trauma With the help of optical fiber for photodynamic therapy, avoiding the trauma and pain caused by surgery 3, low toxicity 5-ALA is the normal metabolism of the body cells, the normal tissues ingest less, metabolism. 4, good selectivity. 4, good selectivity, the main target of attack is the lesion cells in the light area, the normal tissue around the lesion damage is slight. 5, can protect the appearance and important organ function For the face of moderate and severe acne, flat warts, skin cancer, etc. can be effectively killed cancerous tissue, as far as possible to minimize the damage to the epithelial structure of the organs and collagen scaffolding, preserving the integrity of the organ appearance and normal physiological function. 6.No need to avoid light Compared with the traditional photodynamic technology, it avoids the advantages of retention of photosensitizer in the body and long time of avoiding light, 5-ALA is non-photosensitized, fast metabolism and no need to avoid light.