0071643192.pdf

INFECTIOUS DISEASE

Sporotrichosis

■ Infection caused by the traumatic inoculation of Sporothrix shenckii (a fungus)

■ Found on plants and in the soil (classically on rose thorns)

SYMPTOMS/EXAM

■ Incubation period: 1–10 weeks

■ One or more suppurating subcutaneous nodules

■ Normally progress proximally along lymphatic channels

DIAGNOSIS

■ ED=treat based on clinical suspicion

■ Definitive =biopsy/fungal culture

TREATMENT

■ Itraconazole for 3–6 months

■ Disseminated: Amphotericin B

■ Unless disseminated, most can be treated as outpatient

TICK-BORNE ILLNESSES

Lyme Disease

■ The spirochete Borrelia burgdorfei

■ Ticks Ixodes scapularis(deer ticks) andIxodes pacificus

■ Nymph stage (1–2 mm) responsible for most transmission

■ Peak transmission in summer months

■ Endemic foci

■ Northeast Coast (Connecticut, Rhode Island)

■ Midwest (Wisconsin, Minnesota)

■ West Coast (California, Oregon)

SYMPTOMS/EXAM

■ >66% of people do not recall bite.

■ Early localized

■ ~1 week later

■ Flulike symptoms

■ Rash (90%)

■ Erythema migrans (migrans, because it grows)

■ Spreading redness with central clearing (“target lesion”) occurs at

site of bite (average 16 cm diameter). (See Figure 8.2.)

■ Early disseminated

■ Weeks to months after exposure

■ Large joint arthritis

■ Neurological

■ Cranial neuropathies (may mimic Bell palsy)

■ Meningitis

■ Radiculopathy (motor or sensory)

■ Carditis (~7%)

■ Typically AV blocks

■ Late

■ >1 year after exposure

■ Chronic arthritis

■ Peripheral neuropathy

Colorado tick fever is a tick-

borneself-limited viral

infectionthat requires only

symptomatic treatment.

The majority of people with

Lyme disease do not recall a

tick bite.

Target lesion differential:

1. Lyme disease: Single lesion,
   increases in size, central
   clearing


2. Erythema multiforme
   (Stevens-Johnson
   syndrome): Multiple
   lesions with central blister
   or necrosis