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Unusual Breath Odors in Kids

Unusual Breath

Odors & What They Mean

Unusual breath odors are common in kids. Typically there isn’t anything to worry about, but there are some breath odors that indicate an underlying problem.

In children smelly breath that persists throughout the day is most often the result of mouth-breathing, which dries out the mouth and allows the bacteria to grow. Children who consistently breathe through their mouths might have colds, sinus infections, allergies, or enlarged tonsils or adenoidsblocking the nasal passages, so a visit to the pediatrician is in order. Thumbsucking or sucking on a blanket can also dry out the mouth.

Here is a list of some very uncommon, but telltale, odors (mostly from Mace, Goodman, Centerwall, et al: The child with an unusual odor. Clinical Pediatrics 15:57-62, 1976).

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Unusual Breath Odors:

Acetone (fruity smell) – diabetes or acetone, alcohol, phenol, or salicylate ingestionAmmonia – some types of urinary tract infections, or kidney failureAsparagus – eating asparagus (very unusual in children;>))Bitter almonds – cyanide poisoningCat’s urine – odor of cats syndrome (beta-methyl-crotonyl-CoA-carboxylase deficiency)Celery – Oasthouse urine diseaseDead fish – stale fish syndrome (trimethylamine oxidase deficiency)Fresh-baked bread – typhoid feverFoul – tonsillitis, sinusitis, gingivitis, lung abscess, dental cavities, tonsil stones, or gastroesophageal reflux  (some of these are actually quite common)Garlic – arsenic, phosphorus, organic phosphate insecticides, or thallium poisoningHorse-like (also described as mouse-like or musty) – phenylketonuriaRancid butter – odor of rancid butter syndrome (hypermethionemia and hypertyrosinemia)Raw liver – liver failureSweaty socks – odor of sweaty feet syndrome (Isovalryl CoA dehydrogenase deficiency)Sweaty socks – odor of sweaty feet syndrome II (Green acyldehydrogenase deficiency)Violets – turpentine poisoningReport this ad

Three-year-olds often stuff items in their noses, and then forget about them. When my son Kevin was three, he put five peas up his nose before anyone found out! Watch for the combination of smelly breath and a smelly, yellow nasal discharge — especially from one nostril. You and I might not think of stuffing peas up our noses, but three-year-olds think outside the box!

Medical review by: Khanh-Van Le-Bucklin, Liat Simkhay Snyder, Rebecca HicksLast medical review: January 01, 2015Updated: June 18, 2018DISEASES & CONDITIONSMOUTHSCHOOLAGE HEALTH & SAFETYTONSIL STONESTONSILS

Dr. Alan Greene

Dr. Greene is a practicing physician, author, nationaland international TEDx speaker, and global health advocate. He is a graduate of Princeton University and University of California San Francisco.