**Question:** A topical retinoid recently introduced for the treatment of psoriasis is -

A. Tazarotene
B. Ascorbic acid
C. Adapalene
D. Fluocinolone

**Core Concept:**

Psoriasis is a chronic, immune-mediated inflammatory skin disorder characterized by excessive keratinocyte proliferation, impaired differentiation, and angiogenesis. Topical retinoids have been introduced as a treatment option for psoriasis due to their anti-proliferative, anti-inflammatory, and differentiation-enhancing properties. These properties help in reducing plaque thickness, improving skin appearance, and modulating the immune response.

**Why the Correct Answer is Right:**

Tazarotene (A) is a retinoid derivative commonly used in the treatment of psoriasis. It belongs to the class of retinoids known as retinoids with a double bond (ATRODATE). Tazarotene exerts its therapeutic effects by modulating the expression of genes involved in keratinocyte proliferation, differentiation, and inflammation, leading to improved skin conditions.

**Why Each Wrong Option is Incorrect:**

B. Ascorbic acid (Vitamin C) is an antioxidant and has anti-inflammatory properties. However, it does not specifically target the keratinocyte proliferation and inflammation seen in psoriasis. Ascorbic acid is not a standard treatment option for psoriasis.

C. Adapalene (Differin) is another retinoid derivative used in the treatment of acne, not psoriasis. While it has some anti-inflammatory effects, it is not specifically tailored for psoriasis management.

D. Fluocinolone (Intralipid) is a corticosteroid used to suppress inflammation and is not a retinoid. Corticosteroids are not the first choice for treating psoriasis due to their potential side effects and lack of keratinocyte-targeting properties.

**Clinical Pearl:**

Psoriasis treatment is often tailored based on disease severity and patient characteristics. Retinoids, such as tazarotene, are commonly used for mild to moderate cases, while biologics and phototherapy are preferred for more severe cases. Always consider patient-specific factors like skin type, medication history, and potential side effects when choosing a treatment option for psoriasis.