**Question:** Which is not a complication of PUVA therapy?

A. Psoriasis
B. Acne
C. Nausea and vomiting
D. Photosensitive Erythema

**Core Concept:** PUVA therapy is a combination of psoralen (a photosensitizing agent) and ultraviolet A (UVA) radiation used for the treatment of various skin disorders. However, it may cause various complications both in short-term and long-term use.

**Why the Correct Answer is Right:** The correct answer, **B. Acne**, is not a complication of PUVA therapy. Acne is a skin disorder caused by the overproduction of sebum, blocked hair follicles, and inflammation, and is unrelated to the action of psoralen and UVA radiation.

**Why Each Wrong Option is Incorrect:**

**Option A. Psoriasis:** Psoriasis is a chronic inflammatory skin disorder characterized by rapid skin cell production, which can be worsened or induced by PUVA therapy. This makes it a complication of PUVA therapy, not a non-complication.

**Option C. Nausea and vomiting:** These short-term side effects are common reactions to psoralen intake, as it is an oral medication. Although they may resolve after the first few treatments, they are still considered complications of PUVA therapy.

**Option D. Photosensitive Erythema:** Photosensitive Erythema refers to the increased skin sensitivity to UVA radiation after psoralen administration. This reaction is a direct consequence of PUVA therapy and should be considered a complication.

**Clinical Pearl:** While PUVA therapy is a potent tool in dermatology, it carries potential risks that should be carefully weighed against its potential therapeutic benefits for each patient. Adequate counseling of patients about these complications is crucial before initiating treatment.