**Core Concept:** Interdigital dermatitis is a skin condition that occurs between the fingers, often due to repeated trauma, friction, or irritation. In this case, the patient's occupation as a nurse and frequent hand washing contribute to the condition.

**Why the Correct Answer is Right:** The correct answer, C, is "Calcipotriol ointment and NDA (Neosporin, Diclofenac, and Aluminium chloride) cream." Calcipotriol is a synthetic vitamin D analogue that helps in reducing inflammation and promoting healing due to its anti-inflammatory and immunomodulatory effects. NDA cream (Neosporin, Diclofenac, and Aluminium chloride) is a combination of broad-spectrum antibiotic (Neosporin), nonsteroidal anti-inflammatory drug (Diclofenac), and anticholinergic agent (Aluminium chloride) which helps in reducing inflammation, pain, and excessive sweating respectively.

**Why Each Wrong Option is Incorrect:**

A. Calcipotriol ointment alone is incorrect because it lacks the anticholinergic agent (Aluminium chloride) which helps in reducing excessive sweating.

B. NDA cream alone is incorrect as it lacks the anti-inflammatory and immunomodulatory effects of calcipotriol, which are essential for the resolution of interdigital dermatitis.

D. Combination of Calcipotriol ointment and NDA cream is incorrect as it lacks the Aluminium chloride component, which is crucial for reducing excessive sweating.

**Clinical Pearl:** In cases of interdigital dermatitis, combining calcipotriol's anti-inflammatory and immunomodulatory effects with NDA cream's properties helps in holistic management of the condition. The Aluminium chloride component in NDA cream is essential for addressing excessive sweating, which is a common issue in patients with interdigital dermatitis due to the friction caused by wearing gloves or shoes.