Question

A male child was brought with a mild painful swelling on his scalp since the last 3 months, as shown in the image. History reveals that there is a pet dog in the child's house. What is the diagnosis?

• A. Folliculitis
• B. Abscess
• C. Kerion
• D. Scabies

Hint:

Think of a fungal scalp infection transmitted from animals that causes a boggy inflammatory swelling in children.

Answer 1

The Correct Option is C

Alternate analysis -- zoonotic dermatophytosis:

Key clues: child + 3-month painful scalp swelling + pet dog at home.

Pet dogs are reservoirs for zoophilic dermatophytes, particularly $\textit{Microsporum canis}$ and $\textit{Trichophyton mentagrophytes}$. When these infect the scalp hair follicles and provoke a strong cell-mediated immune response, the result is a $\textbf{Kerion}$ -- a boggy, raised, suppurative inflammatory mass with pus-discharging follicles (honeycomb pattern).

Differentiating features:

• Folliculitis: pustular, superficial, acute
• Abscess: bacterial, no honeycomb pattern, no fungal aetiology
• Scabies: burrows, interdigital spaces, intense pruritus -- not a scalp mass

Kerion is treated with systemic antifungal therapy ($\text{griseofulvin}$ orally). Topical antifungals are insufficient as the infection is deep in the follicle.

\[\boxed{\text{Kerion}}\]