Bittu, 6-yr-old boy presents with small hypopigmented scaly macules on cheek. Some of his friends also have similar lesions. Most probable diagnosis is?
**Core Concept**
The condition described is a classic example of a dermatological disorder caused by a fungal infection, which is highly contagious and often affects children in a community setting.
**Why the Correct Answer is Right**
The most probable diagnosis is **Pityriasis versicolor (Malassezia folliculitis)**, also known as Tinea versicolor, caused by the yeast-like fungus Malassezia. This condition presents with small, hypopigmented scaly macules, which are often seen on the face, particularly on the cheeks, chest, and back. The lesions are caused by the overgrowth of Malassezia species, which are normally present on the skin surface. The condition is contagious and can be spread through direct contact with an infected person or by sharing personal items.
**Why Each Wrong Option is Incorrect**
**Option A:** **Pityriasis alba** is a condition characterized by small, round, hypo- or hyperpigmented patches on the face, but it is not contagious and typically affects children with atopic dermatitis.
**Option B:** **Tinea corporis** (Ringworm) is a fungal infection that affects the skin, but it typically presents with a ring-shaped lesion with central clearing, which is not seen in Pityriasis versicolor.
**Option C:** **Seborrhoeic dermatitis** is a condition that presents with a scaly, erythematous rash, often on the scalp and face, but it is not contagious and has a different clinical appearance.
**Clinical Pearl / High-Yield Fact**
Pityriasis versicolor is often seen in children and young adults, particularly those with oily skin, and can be treated with topical antifungal agents or oral medications.
**Correct Answer:** D. Pityriasis versicolor (Malassezia folliculitis)