A 3-year-old child develops fever with "dew drop-like vesicles" starting on the trunk and later spreading to the limbs. There are no signs of neck rigidity. What is the likely diagnosis?

1. A

   Measles

2. B

   Chickenpox

3. C

   Scarlet fever

4. D

   Rubella

Appeared in: UP NHM CHO 7 Sept 2022 (Shift-2)

Explanation

• The key diagnostic feature described is the "dew drop-like vesicles," which are small, clear, fluid-filled blisters on a red base. This is the hallmark sign of Chickenpox.
• The rash in Chickenpox is pleomorphic, meaning lesions in various stages of development (spots, blisters, and crusted scabs) are present at the same time.
• The distribution of the rash, starting on the trunk and then spreading to the face and limbs (centripetal spread), is the classic pattern for Chickenpox.
• The illness is caused by the Varicella-zoster virus and is typically accompanied by fever and intense itching.

Why Other Options Were Wrong

• Option A: Measles presents with a reddish-brown maculopapular (flat and raised spots) rash, not vesicles. It is also characterized by Koplik's spots, cough, coryza, and conjunctivitis.
• Option C: Scarlet fever, a bacterial infection, causes a fine, red, 'sandpaper-like' rash. It does not produce vesicles. Other key signs include a strawberry tongue and Pastia's lines.
• Option D: Rubella (German measles) causes a pinkish, maculopapular rash that is less prominent than measles and does not form vesicles. It is strongly associated with swollen lymph nodes behind the ears and at the back of the neck.

Related Visual

Clinical Relevance

• Nursing practice connection: Use the key finding related to Differential diagnosis of common childhood exanthems (rashes) to guide bedside assessment, documentation, and the next nursing action.
• Recognizing the classic signs of Chickenpox is crucial for prompt diagnosis and implementation of isolation precautions (airborne and contact) to prevent its spread in community and healthcare settings.
• A critical nursing intervention is educating parents to avoid aspirin for fever management in children with viral illnesses like Chickenpox, due to the risk of developing Reye's syndrome, a rare but serious condition that causes swelling in the liver and brain.
• Vaccination with the Varicella vaccine is the most effective way to prevent Chickenpox and its complications.

How to Approach the Question

• First, identify the most specific and unique clinical sign described in the question stem. In this case, it is the "dew drop-like vesicles."
• Recognize this description as a pathognomonic (uniquely characteristic) sign for a particular disease.
• Next, consider the distribution of the rash: starting on the trunk and spreading outwards. This is known as centripetal spread.
• Combine these two key features (vesicular rash + centripetal spread) to arrive at the most likely diagnosis.
• Evaluate the other options by recalling their distinct rash characteristics (e.g., maculopapular for measles/rubella, sandpaper for scarlet fever) to confirm they do not fit the clinical picture.

Concept Tested & Keywords

• Concept Tested: Differential diagnosis of common childhood exanthems (rashes).
• Stem keywords: 3-year-old child, fever, dew drop-like vesicles, trunk, spreading to limbs
• Lead-in keywords: likely diagnosis
• Clinical cues: The description 'dew drop-like vesicles' is a pathognomonic sign for Chickenpox.
• Clinical cues: The rash distribution starting on the trunk (centripetal) is characteristic of Chickenpox.

Question ID

Q9z_0IfpRf5SnQgACpHajy

Copy ID

Reference Book

E6 Medicine Harrison 22e Part 1 p. 1682-1684

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 2024-2026