For the treatment of skin diseases such as psoriasis and atopic dermatitis, pharmaceutical products such as topical drugs (topical cream), oral drugs (medicinal drinks) are usually used. However, depending on the patient, they are not versatile because sometimes they are ineffective or have side effects, etc.

In some skin diseases, the healing effect can also be recognized by exposure to a specific wavelength of ultraviolet light. Although the medical equipment using ultraviolet mercury lamp has been put into practical application, the compact, wavelength optional and long service life of deep UV LED can achieve a more compact and safe equipment compared with traditional equipment.