A 5-year-old boy presents with painful defecation and new-onset constipation. His parents have noticed small amounts of bright-red blood around the stool. Examination reveals a bright-red, sharply demarcated, circumferential perianal rash without a discrete anal fissure. A perianal swab is positive for group A Streptococcus.
What is the most appropriate treatment?
A. Topical mupirocin alone
B. Oral amoxicillin
C. Oral trimethoprim-sulfamethoxazole
Correct Answer: B. Oral amoxicillin
Explanation
This child has perianal streptococcal dermatitis, an important pediatric condition that can easily be mistaken for simple constipation with an anal fissure.
The major clue is the bright-red, sharply demarcated perianal erythema, sometimes described as a “red lipstick” appearance. Children may present with perianal pain, itching, painful defecation, stool withholding, constipation, and occasionally blood-streaked stool.
The discomfort associated with defecation may cause the child to withhold stool, leading clinicians or parents to assume that constipation is the primary problem.
When group A Streptococcus (GAS) is identified, oral penicillin or amoxicillin is an appropriate first-line treatment. A perianal swab for rapid GAS testing and/or culture can help establish the diagnosis.
Board Pearls
Think perianal bacterial dermatitis when you see:
- Bright-red, sharply demarcated perianal erythema
- Pain or itching around the anus
- Painful defecation
- New-onset stool withholding or constipation
- Bright-red blood associated with defecation
- No typical discrete anal fissure explaining the symptoms
- Group A Streptococcus on perianal testing
How Do You Differentiate It From an Anal Fissure?
A child with functional constipation and an anal fissure typically has a history of hard, large-diameter stools followed by painful defecation and a visible discrete fissure.
With perianal bacterial dermatitis, the key finding is the characteristic homogeneous, bright-red, sharply demarcated perianal rash.
That distinction is exactly the type of clinical reasoning you need for the pediatric board examination.
This Is How the Last-Minute Pediatric Question Bank Helps You Prepare
Passing the pediatric boards is not simply about memorizing thousands of isolated facts.
You need to recognize clinical patterns.
You need to identify the one or two clues that change the diagnosis.
And you need to know what the examiner is really asking.
The Last-Minute Pediatric Question Bank was created around these principles.
Instead of overwhelming you with unnecessary information, our questions emphasize the high-yield concepts, diagnostic clues, treatment choices, and Board Pearls that you need to recognize quickly.
Real-Life Clinical Scenarios With Board-Relevant Concepts
Questions such as the case above begin with situations that pediatricians may encounter in everyday practice.
A child with constipation and rectal bleeding sounds common.
But add a bright-red, sharply demarcated perianal rash, and suddenly the diagnosis changes.
That is the skill we want you to develop:
Recognize the clue → identify the diagnosis → choose the appropriate management.
Our Last-Minute Question Bank uses clinical scenarios to reinforce these connections and help you approach unfamiliar questions using the same reasoning.
More Than 2,500 Questions Focused on High-Yield Pediatrics
The Last-Minute Pediatric Question Bank includes more than 2,500 questions covering high-yield pediatric topics.
The goal is not simply to tell you whether your answer was right or wrong. Questions are designed to reinforce:
Key diagnostic clues → Most likely diagnosis → Best next step → Treatment → Board Pearl
This makes each question an opportunity for rapid review.
Why This Matters Before the Pediatric Board Exam
As the examination approaches, trying to reread every textbook chapter may become increasingly inefficient.
Your final review should help you rapidly recognize:
What is distinctive about this disease?
What clue is the examiner giving me?
What diagnosis should immediately come to mind?
What is the next best step or treatment of choice?
These are the concepts emphasized throughout the Last-Minute Pediatric Question Bank.
The purpose is simple: turn high-yield pediatric knowledge into board-style clinical reasoning that you can retrieve quickly when you need it most.
Make Every Question Part of Your Last-Minute Review
Don’t just count how many questions you complete.
Ask yourself what one Board Pearl you should remember from each question.
By exam day, those repeated clinical patterns, key words, diagnostic clues, and treatment principles can become some of the most valuable tools in your board preparation.
Prepare smarter. Recognize the clues. Master the high-yield concepts.