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

Step 1: Identify the key features. A child with a mildly painful, spongy scalp swelling persisting for 3 months, with a history of a pet dog at home. This epidemiological clue (zoonotic exposure) is critical.

Step 2: Understand Kerion. Kerion celsi is an acute inflammatory reaction caused by a dermatophyte fungal infection of the hair follicles of the scalp. It represents a hypersensitivity (immune-mediated) response to the fungal infection rather than direct infection alone.

• Typically occurs in children.
• Presents as a raised, boggy, spongy, painful swelling on the scalp with follicles discharging pus (honeycomb appearance).
• Sinus formation may occur; rarely mycetoma-like grains are produced.
• Causative organisms: Trichophyton verrucosum, T. mentagrophytes, and Microsporum canis (transmitted from animals including dogs and cattle).

Step 3: Rule out other options.

• Folliculitis: superficial infection of follicles; presents as pustules, not a boggy mass.
• Abscess: bacterial collection; acute onset, without the characteristic honeycomb fungal pattern.
• Scabies: mite infestation causing intense itching; does not cause scalp swelling of this nature.

Step 4: Conclusion. The combination of scalp boggy swelling in a child with pet dog exposure = Kerion. Treatment is with oral griseofulvin. Answer: Kerion.