The following drug is effective in treatment of ptyriasis versicolor –
**Core Concept**
Pityriasis versicolor (PV) is a common skin infection caused by the yeast Malassezia, leading to patches of discoloration and scaling on the skin. Effective treatments aim to reduce the population of Malassezia and prevent its overgrowth.
**Why the Correct Answer is Right**
The correct answer is a topical antifungal agent that inhibits the growth of Malassezia by interfering with its cell membrane function. It is often used in combination with other treatments to enhance its efficacy. The mechanism of action involves the inhibition of squalene epoxidase, an enzyme essential for the production of ergosterol, a critical component of the fungal cell membrane.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as it is a topical corticosteroid, which may exacerbate PV by promoting the growth of Malassezia.
* **Option B:** This option is incorrect as it is a topical antibiotic, which is ineffective against fungal infections like PV.
* **Option C:** This option is incorrect as it is a topical retinoid, which may have some benefits in treating PV but is not the most effective treatment option.
**Clinical Pearl / High-Yield Fact**
When treating PV, it is essential to use a combination of treatments, including topical antifungals, azoles, and keratolytics, to effectively reduce the population of Malassezia and promote skin healing.
**Correct Answer:** C. Clotrimazole