Not any more, mostly
Puva stands for "psoralen plus ultraviolet-a" - you take a drug called psoralen, which sensitizes your skin to long-wave uv light, then you go in a uv light box.
It was used to treat psoriasis
and other skin diseases
, but in recent years it has largely been replaced by narrow-band uvb
light treatment, which works better and avoids the risks of psoralen, such as sunburn