aroma of freshly baked bread, yellow fever’s butcher shop smell, smallpox’s menagerie odor, scrofula’s odor of stale beer, diphtheria’s sweet smell, and rubella’s scent of freshly plucked feathers Medications also have distinguishing odors Penicillins give off an ammoniacal scent, whereas cephalosporins are noted to have a musty odor Topical benzoyl peroxide, applied in large quantities, emits a pungent, pervasive aroma Dermatologic Conditions Many dermatologic diseases ( Table 50.1 ) are associated with specific odors Any cause of hyperhidrosis results in an offensive body odor Hidradenitis has a characteristic pungent odor, and Darier disease (keratosis follicularis) is noted to have a pervasive aroma of burned tissue An abscess or cellulitis is identified by the characteristic odors of the responsible microorganisms In burn patients, there is the typical odor of charred flesh, which, when infected with Pseudomonas aeruginosa, takes on a characteristic sweet, grapelike odor Foreign Bodies Foreign bodies can produce a foul odor that results from secondary bacterial colonization or infection Foreign body odors can be localized to a particular orifice, or they may pervade a patient’s clothing, body, and surrounding environment Foul-smelling, fetid, or feculent odors indicate anaerobic infections, a sickly sweet odor is associated with Escherichia coli, and a mousy odor is associated with Clostridium Orifice Odors Specific orifice odors can be diagnostic of infectious disease processes Oropharynx A healthy mouth does not give off an offensive odor Halitosis, or bad breath, is the result of a release of volatile sulfur compounds formed when the oral flora metabolizes amino acids from compounds in the saliva that adhere to the tongue, teeth, and gums Halitosis is increased in states of diminished solid and liquid intake Tonsillitis (see Chapter 74 Sore Throat ) has an offensive odor, and group A β-hemolytic streptococcus gives off a characteristic “strep breath” smell Dental abscesses (see Chapter 117 Dental Emergencies ), gum or periodontal disease, and acute ulcerative gingivitis (Vincent angina, or trench mouth) are associated with a penetrating, offensive odor often described as metallic in nature The oropharynx is also the portal of exit for deeper infections Lung abscesses, empyema, bronchitis, and bronchiectasis result in foul breath and sputum Nasal