Internal Medicine

P1: RLJ/OZN P2: KUF

0521779407-D-01 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 7:41

Diphtheria 487

Diphtheria.........................................

RICHARD A. JACOBS, MD, PhD

history & physical

History

■Etiologic agent Corynebacterium diphtheriae, an aerobic, pleomor-

phic, Gram-positive bacillus

■Organism not very tissue-invasive; produces disease by local infiltra-

tion of mucous membranes of the respiratory tract and by produc-

tion of toxin that primarily affects the heart and peripheral nerves

■Humans only known reservoir; disease spread by respiratory secre-

tions from those who have active disease or those who are asymp-

tomatic respiratory carriers, and from direct contact with cutaneous

lesions

Signs & Symptoms

■Locally invasive disease:

➣Nasal – serosanguinous or purulent nasal discharge; membrane,

if present, is minimal; toxin production from this limited form of

disease is rare

➣Pharyngeal – fever, sore throat, dysphagia and cervical adenopa-

thy with membrane formation on the tonsils, soft palate and

uvula; membrane initially white but becomes gray within days

and is associated with bleeding of underlying mucosa when

removed

➣Laryngeal – hoarseness, stridor, dyspnea and airway occlusion

can result as infection and membrane spread to larynx and tra-

cheobronchial tree; toxin production in pharyngeal and laryn-

geal disease is common

➣Cutaneous – classic description is chronic ulcer with membrane

formation; however, most skin lesions from which C. diphthe-

riae is isolated look like other chronic, nonhealing ulcers; toxin

production rare in cutaneous disease, but skin lesions serve as

major reservoir for spread of infection

■Toxin-mediated disease:

➣Local – paralysis of soft palate followed by cranial neuropathies

➣Peripheral neuropathy – usually proximal motor neuropathy

of lower extremities; other areas (upper extremities, trunk)

less commonly involved; peripheral sensory neuropathy also