Body Odor In Babies: What Is Normal And How To Deal With It

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Body odor in babies is distinctive, and they may often smell of baby products or milk. However, babies who are not bathed on time or wear unclean clothes can have a sour or pungent odor. Most mothers could sense their babies smelling and try to keep them clean.

Some babies can even leave a cake or fruity odor. On the other side, some may smell rotten fish or cabbage. You may seek medical care to determine the causes of unusual body smell in babies. Read on to know the causes, treatment, and remedies for various body odors in babies.

Normal Types Of Body Odor In Babies

Lack of hygiene may lead to foul body odor in babies

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The following body odors are very common among babies, and you need not worry about it.

1. Milky odor 

Babies often smell of milk. The peculiar body odor fades away when your baby’s milk intake reduces, and they graduate to a solid diet.

2. Sour odor

Sometimes your baby might have a sour body odor, especially when they spit-up. Babies may have unpleasant body odor when the dirt and sweat are trapped in their underarms, neck area, or skin folds. The lack of proper hygiene can lead to fungal infection, irritation, and redness of the skin.

Common Causes Of Body Odor In Babies

Sweat, heat, and pollution may cause a foul body odor

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Some of the common causes of baby body odor may include:

  • Pollution and heat
  • Dust
  • Dietary Imbalance
  • Dressing
  • Unhygienic surroundings
  • Sweat
  • Urine
  • Metabolic disorders

Abnormal Types Of Body Odor In Babies

If your baby has a weird body odor, it may indicate an underlying health problem, such as a metabolic disorder. Some abnormal body odors in babies are the following.

1. Fish odor

Trimethylaminuria may cause a foul body odor in babies

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Babies with primary trimethylaminuria or the fish odor syndrome (FOS) will have a rotten fish smell in their breath, urine, and sweat. This is a genetic disorder caused by an enzyme deficiency that prevents their body from breaking down trimethylamine (1).

Trimethylamine (TMA) is produced in the intestine when foods, such as eggs, legumes, some vegetables, fish, etc. are digested by colonic bacteria. TMA diffuses through the intestinal tract membrane and reaches the liver where it is metabolized into odorless trimethylamine oxide (TMAO).

Babies with hepatic diseases, such as viral hepatitis, may have rotting fish odor since TMA is not metabolized into TMAO in their liver. Kidney disorders may cause fishy smell due to bacterial overgrowth in the intestine. Trimethylaminuria caused by hepatic or renal diseases is known as secondary trimethylaminuria (2).

2. Maple syrup odor

If your baby’s urine smells like maple syrup or cake, it can be because of maple syrup urine disease (MSUD). This is a rare genetic disorder due to the deficiency of an enzyme complex that breaks down certain amino acids (proteins) in the body. The accumulation of these amino acids and their toxic byproducts may give urine a distinct sweet smell. If left untreated, babies may develop neurological dysfunction and other neurological problems, such as seizures (3).

3. Musty odor 

Phenylketonuria (PKU) is a congenital metabolic disorder that causes your baby’s body to emit a musty odor. Babies with this genetic problem may have decreased metabolism of the amino acid called phenylalanine. If untreated, the accumulation of phenylalanine in the blood can lead to learning disabilities, behavioral problems, epilepsy, lighter skin color, tremors, etc. (4)

4. Fruity odor

Fruity-smelling breath is one of the indicators of diabetes type 1 in babies. The fruity scent occurs due to diabetes ketoacidosis (DKA), a complication of diabetes type 1 due to the buildup of ketones in the body. If left untreated, diabetic ketoacidosis can be life-threatening in babies (5).

5. Cabbage odor

Babies with tyrosinemia type 1 may have a cabbage-like odor. This is a genetic metabolic disorder where an enzyme deficiency causes the accumulation of amino acid tyrosine in the blood. If left untreated, this may cause developmental delays, liver failure, enlargement of the spleen, and other fatal problems (6).

6. Sweaty feet odor

Isovaleric acidemia may cause a foul body odor in babies

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Isovaleric acidemia and glutaric acidemia type II are disorders causing “sweaty feet” smell in babies. Although it is rare, you may have to distinguish these conditions from excessive sweating of the feet that itself results in the odor.

  • Isovaleric acidemia is a rare disorder caused by an inability to break down isovaleric acid. Its buildup results in sweaty feet odor and other symptoms, such as lethargy, failure to thrive, seizures, etc(7).
  • Glutaric acidemia type II (GA2) is an inherited disorder that interferes with the metabolism of fats and proteins in the body. This may result in sweaty feet odor in babies. The symptoms may vary depending on the severity of the disorder. GA2 could lead to lethargy, poor feeding, behavioral changes, and vomiting. The most severe form of the disorder is seen within the first four weeks after the birth, and the baby may have brain malformations, and heart and liver enlargement (8).

If you notice any of these or other strange smells, call your child’s doctor for advice. Keep in mind that most of these conditions are rare, and there could be another explanation for the smell. Unpleasant body odor due to poor hygiene alone can be dealt with improved personal hygiene.

How To Deal With Your Baby’s Body Odor?

Here are a few ways in which you can take into consideration if your baby has body odor:

  • Bathe the baby using baby shampoos
  • Always pat dry and apply moisturizer after bath
  • Use baby powders to reduce sweating. Ensure that the baby doesn’t inhale any of the powder.
  • Use waterproof baby feeding aprons while feeding
Waterproof bibs may help prevent bad odor

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  • Clean baby’s face and neck after eating
  • Dress up your baby in light clothing during summer to avoid excess sweating
  • Always use clean and dry socks and shoes
  • Wash baby’s clothes often and dry them well
  • Change diapers on time
  • Wipe or wash and pat dry genital area while changing diapers

Body odor in babies is a natural occurrence that disappears as they grow. But if your baby smells different from the distinctive milky or sour odor, it may be due to an underlying condition. Typical body odor in babies is generally due to their diet, sweat, or dressing. If your baby presents uncommon smells such as fishy odor or fruity odor, do not panic. Instead, you may try some effective hygiene practices for managing the odor. However, consult a doctor if the odor doesn’t disappear for early detection of any issue and timely treatment.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
1. Trimethylaminuria (“fish odour syndrome”); National Health Service, UK
2. Jeffrey Messenger, et al.; A Review of Trimethylaminuria: (Fish Odor Syndrome); The United States National Library of Medicine
3. Maple syrup urine disease (MSUD); The National Organization for Rare Disorders
4. Phenylketonuria (PKU); National Health Service, UK
5. Signs of Diabetes in Toddlers, Babies & Infants; Juvenile Diabetes Research Foundation
6. Tyrosinemia type I; The National Organization for Rare Disorders
7. Isovaleric acidemia; The United States National Library of Medicine
8. Glutaric acidemia type 2; The National Center for Advancing Translational Sciences
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Dr Bisny T. Joseph

Dr. Bisny T. Joseph is a Georgian Board-certified physician. She has completed her professional graduate degree as a medical doctor from Tbilisi State Medical University, Georgia. She has 3+ years of experience in various sectors of medical affairs as a physician, medical reviewer, medical writer, health coach, and Q&A expert. Her interest in digital medical education and patient education made...
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Dr. Richard Mario Lurshay

Dr. Richard Mario Lurshay is a young and talented pediatrician, well known for his work with children. After completing his post-graduation in Pediatrics, he completed his training in Pediatric Nutrition from Boston University School of Medicine (USA). He is an esteemed Life Member of National Academy of Medical Sciences (NAMS), National Neonatology Forum (NNF) and Indian Academy of Paediatrics (IAP)....
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