What is the cause of Streptococcal (Strep) diaper rash in infants?

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Last updated: March 24, 2025View editorial policy

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From the Guidelines

Strep diaper rash in infants is caused by Group A Streptococcus bacteria, which can enter through small breaks in the skin, as indicated by studies such as 1. The rash appears bright red with well-defined edges and may have small red dots or pustules.

  • The bacteria can originate from various sources, including the anal canal or vagina, and can be introduced through small breaks in the skin.
  • Keeping the diaper area clean and dry, changing diapers frequently, and applying a barrier cream containing zinc oxide can help manage the condition.
  • Warm baths with a small amount of baking soda can soothe the skin, and allowing for diaper-free time can help the area heal.
  • It is essential to complete the full course of antibiotics, even if the rash improves quickly, to prevent recurrence, as suggested by 1.
  • If the rash doesn't improve within 48-72 hours of starting antibiotics, it is crucial to contact a healthcare provider, as a different antibiotic may be needed or there could be another cause for the rash.
  • The most recent and highest quality study, 1, although focused on skin and soft-tissue infections, supports the idea that streptococci are a primary cause of such infections, further emphasizing the role of Group A Streptococcus in Strep diaper rash.

From the Research

Causes of Streptococcal (Strep) Diaper Rash

There are no direct research papers provided that specifically discuss the cause of Streptococcal (Strep) diaper rash in infants. However, the provided studies discuss the causes of diaper dermatitis, which may be related to Streptococcal (Strep) diaper rash.

Diaper Dermatitis Causes

  • Irritant reaction to urine and feces, facilitated by occlusive conditions under the diaper, leading to hyperhydration of the stratum corneum 2
  • Diaper pressure and friction can increase the risk of skin inflammation, which also opens the skin up to other irritant agents, allergens, and infectious agents, such as candida albicans 2
  • Friction, excessive hydration, varying pH, and constant contact with urine and feces, which are highly irritant to the skin 3
  • Candida albicans and Staphylococcus aureus are most frequently isolated from the affected area and are thought to have a predominant role in diaper dermatitis 3

Skin Conditions in the Diaper Area

  • Diaper dermatitis may account for up to 25% of dermatology visits to health care providers during the first year of life 4
  • A number of skin conditions that can occur anywhere on the skin may present with distinctive findings in the diaper area 4
  • Appropriate skin care can help to prevent the occurrence of diaper dermatitis and to speed up the healing of affected skin 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Differential diagnoses of diaper dermatitis.

Pediatric dermatology, 2018

Research

Differential Diagnosis of Diaper Dermatitis.

Clinical pediatrics, 2017

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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