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). Re-published by Alan Greene MD FAAP

  •  Acetone—diabetes or acetone, alcohol, phenol, or salicylate ingestion
     
  •  Ammonia—some types of urinary tract infections, or kidney failure
     
  •  Bitter almonds—cyanide poisoning
     
  •  Cat’s urine—odor of cats syndrome (beta-methyl-crotonyl-CoA-carboxylase deficiency)
     
  •  Celery—Oasthouse urine disease
     
  •  Dead fish—stale fish syndrome (trimethylamine oxidase deficiency)
     
  •  Fresh-baked bread—typhoid fever
     
  •  Foul—tonsillitis, sinusitis, gingivitis, lung abscess, or dental cavities
     
  •  Garlic—arsenic, phosphorus, organic phosphate insecticides, or thallium poisoning
     
  •  Horse-like (also described as mouse-like or musty)—phenylketonuria
     
  •  Rancid butter—odor of rancid butter syndrome (hypermethionemia and hypertyrosinemia)
     
  •  Raw liver—liver failure
     
  •  Sweaty socks—odor of sweaty feet syndrome (Isovalryl CoA dehydrogenase deficiency)
     
  •  Sweaty socks—odor of sweaty feet syndrome II (Green acyldehydrogenase deficiency)
     
  •  Violets—turpentine poisoning