Phototherapies

The beneficial effects of sun exposure on certain skin diseases and conditions have been known for centuries.

Photodynamic therapy involves the use of visible light. Phototherapy does not use an exogenous photosensitizing drug but, rather, an endogenous target molecule. Photochemotherapy uses an exogenously administered photosensitizing drug or molecule.

UV or visible light radiation is absorbed by target molecules or "chromophores" to induce a therapeutic response.

Prior to beginning phototherapies, a careful patient history must be taken to determine whether or not patients are taking photosensitizing drugs for other medical conditions. Many drugs are photosensitizing and include the following: antibiotics, phenothiazines, diuretics, nonsteroidal anti-inflammatory agents, and sedative hypnotics.