All Topics
Fesses rouges bébé

Why does baby have red buttocks?

A baby is not immune to skin problems. On the contrary, the fragility of children's skin makes them particularly prone to irritations. Most frequently, these occur in the nappy area and manifest as uncomfortable, even painful, redness for babies. How can you spot nappy rash? What is its origin? Find the answers to these questions here.

Published April 11, 2024, by Pauline, Head of Scientific Communication — 4 min read

How to identify nappy rash in an infant?

Nappy rash is an extremely common skin inflammation in babies. It is estimated that it affects approximately eight out of ten infants. The swollen appearance and red hue of the buttocks are the main warning signs. The skin in this area may also feel warm to the touch. In the absence of a suitable treatment, the redness can worsen and spread to other parts of the body. Nappy rash, also known as diaper dermatitis, is easy to cure, provided that certain appropriate habits are adopted and the right care is used.

Not all infants react the same way when faced with nappy rash. However, while some are more bothered than others, most babies have more difficulty sleeping and moving peacefully. Each movement tugs at their delicate and painful skin , which can lead to constant crying. Moreover, redness in the buttock area can be accompanied by itching, which can be challenging for babies to endure.

What are the causes of nappy rash in babies?

Various factors can trigger the onset of redness on infants' buttocks. Most commonly, nappy rash is caused by a drying out of the child's skin, due to friction from nappies. An intolerance to certain substances contained in wipes, nappies, soaps or creams can also be responsible. It has also been identified that digestive or urinary disorders are aggravating factors of nappy rash. Indeed, diarrhoea, caused by teething, food intolerance or the use of antibiotics, perpetuates the irritation by causing an increase in the activity of faecal enzymes, which damages the epidermis.

Furthermore, prolonged exposure to urine and faecal matter, coupled with the occlusion caused by the constant wearing of nappies, can contribute to the maintenance of nappy rash. Indeed, this leads to thealkalisation of the skin's pH, which alters the skin microbiota and damages the stratum corneum. Friction against the skin and maceration can cause a breakdown of the skin barrier and increased permeability to potentially irritating substances. These factors predispose the skin tomicrobial invasion and inflammation. The fungi Candida albicans and the bacteria Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli are indeed commonly associated with nappy rash. This alteration of the skin microbiota can trigger the release of histamine and pro-inflammatory prostaglandins, exacerbating irritation and redness.

If your baby has a persistent nappy rash for several days despite the administration of care, it is necessary to seek medical advice.


  • KANTI V. & BLUME-PEYTAVI U. Prevention and treatment of nappy rash. Paediatric Dermatology (2018).

  • MICETIC-TURK D. & al. Diagnosis and management of nappy rash in infants with a focus on skin microbiota in the nappy area. International Journal of Dermatology (2018).

  • CICCONE A. & VARBANOV M. Diaper rash, advice and treatments. Pharmaceutical News (2020).


Understand your skin
and its complex needs.