Rosen & Barkin's 5-Minute Emergency Medicine Consult (631 page)

• Restrict excess calcium from the diet.
  
• Monitor for complications related to chronic steroid therapy
  

• Evaluate patients with chest radiographs to determine stage and progression of disease.
  
• Prednisone is treatment of choice for exacerbations of disease.
  
• Monitor for signs of hypercalcemia and related complications.
  
• Be aware of acute neurologic and ocular sequelae.
  

• Baughman RP. Pulmonary sarcoidosis.
  Clin Chest Med
  . 2004;25:521–530.
  
• Fauci AS, Braunwald E, Kasper DL, et al.
  Harrison’s principles of internal medicine
  . 17th ed. New York, NY: McGraw-Hill Professional; 2008.
  
• Iannuzzi MC, Rybicki BA, Teirstein AS.
  Sarcoidosis. N Engl J Med
  . 2007;357:2153–2165.
  
• King TE. Sarcoidosis. Updated Apr 18, 2011. Available at
  www.UpToDate.com
  . Accessed on January 2013.
  

See Also (Topic, Algorithm, Electronic Media Element)

• Dyspnea
  
• HIV/AIDS
  
• Hyperparathyroidism
  
• Tuberculosis
  

CODES

• 135 Sarcoidosis
  
• 517.8 Lung involvement in other diseases classified elsewhere
  

BASICS

• Mites mate on skin surface and gravid female burrows into stratum corneum to lay eggs:
  
  • Animal scabies can burrow but cannot reproduce on human hosts
    
• Symptoms result from delayed type IV hypersensitivity reaction to mite, eggs, saliva, and feces:
  
  • Inflammatory reaction leads to intense pruritus, which is the hallmark of the disease
    
  • Crusted Norwegian scabies is characterized by large numbers of mites and is seen in the immunocompromised, disabled, and institutionalized:
    
    • More infectious than ordinary scabies due to high mite count
      
• Despite >2,500-yr existence, an effective way to prevent scabies is still not known
  
• Secondary infection is common and, as such, the morbidity associated with scabies may be underestimated
  
• Scabies is a major global health problem in many crowded, resource-poor communities
  
• Infestations become secondarily infected and epidemic acute poststreptococcal glomerulonephritis and rheumatic heart disease are often associated with endemic scabies
  

• Scabies manifests itself in various forms in children and differs from that in adults:
  
  • More inflammatory (vesicular or bullous)
    
  • Involvement of face, scalp, palms, or soles
    
• Highest prevalence is in children <2 yr old
  

• Epidemiology:
  
  • Over the past 2 decades, the number of patients with scabies is increasing
    
  • Up to 300 million cases yearly
    
  • Burden of disease is highest in tropical countries
    
• Produced by the human scabies mite,
  Sarcoptes scabiei
  var.
  hominis
  , or from animal mites
  
• Transmitted by prolonged (15–20 min) direct skin-to-skin contact or, less commonly, by infested bedding or clothing:
  
  • It is a disease of overcrowding and poverty, rather than a reflection of poor hygiene
    
  • Probability of being infected is related to number of mites on infected person and length of contact
    
  • Family members, sexual contacts, and institutional settings are at high risk for transmission
    
  • Schools do not ordinarily provide the level of contact necessary for transmission
    
• Mites subsist on a diet of dissolved human tissue (do not feed on blood) and can live up to 3 days off a host’s body
  
• On average, the number of mites on a host at any time is ∼5–15:
  
  • Main difference between crusted Norwegian scabies and ordinary scabies is the number of mites present on the host
    
  • Patients with crusted Norwegian scabies are infected with thousands or up to a million mites
    

DIAGNOSIS

Generalized and intense itching that is worse at night and usually spares the head and face

• Site, severity, duration, and timing of itch
  
• History should include family members and close contacts
  
• Generalized, intensely pruritic eruption:
  
  • Pruritus is intensified at night
    
• Onset 10–30 days after exposure and infestation; reinfestation provokes immediate (within 1–3 days) pruritus:
  
  • Patients with crusted Norwegian scabies are usually immunocompromised, have a decreased inflammatory response, and have less pruritus
    

• Often minimal cutaneous findings
  
• Primary lesion: Linear, elevated, white-gray burrow (up to 1 cm long, width of a human hair) with small vesicle containing black dot at the end (mites barely visible to naked eye):
  
  • Found symmetrically in web spaces of fingers, flexor surfaces of wrists and elbows, waistline, periumbilical skin, axillary folds, buttocks, penis, scrotum, vulva, and areola
    
  • Head and neck rarely affected in adults but more commonly in infants and children
    
• Secondary lesions: Inflammatory papules, nodules, excoriations, or secondary impetigo or folliculitis seen on back, shoulders, axilla, waist, buttocks, and flexor aspects of elbows:
  
  • Secondary lesions are usually more numerous and prominent than burrows but also may be few if topical steroids used
    
• Longstanding infestation results in chronic excoriation, eczematization, and hyperpigmented and lichenified skin
  
• Crusted Norwegian scabies produces gross scaling with hyperkeratotic plaques on hands, feet, scalp, and pressure-bearing areas:
  
  • Scales can become warty
    
  • Fissures may appear
    
  • Nail involvement is common
    
• Genitalia should be examined in all instances of suspected scabies
  

• Eruption may be seen from head to toe
  
• Vesicles are often found in infants due to their predisposition for vesicle formation
  
• Neonatal scabies is associated with poor feeding, poor weight gain, and super infection
  

• Careful history and skin exam for characteristic lesions
  
• The diagnosis is easily missed and should be considered in any patient with persistent generalized pruritus
  
• Factors related to missed diagnosis in patients admitted through the ED:
  
  • Overcrowding, time constraints, and lower patient illness severity scores
    

• May be indicated in immunocompromised patients or in patients with systemic infection:
  
  • Elevated IgE and IgG and peripheral eosinophilia can be seen in crusted scabies
    
• New diagnostic lab studies are being developed (circulating IgE levels, PCR, ELISA, and DNA finger printing)
  
• When endemic, empiric treatment may be more cost effective than lab testing
  
• Consider screening for other STDs
  

Epiluminescence microscopy and noncomputed dermoscopy are noninvasive, simple, accurate, and rapid imaging techniques

• Scrape skin at burrows or under fingernails with no. 15 blade and mineral oil (adheres scraped material to blade) and observe under low-power microscope for mites, eggs, or fecal material; may be operator dependent
  
• A negative scraping does not exclude infestation due to low number of mites in classic scabies:
  
  • Sensitivity <50% and is affected by number of sites sampled and sampler’s experience
    
• Skin biopsy may confirm diagnosis but findings may also be absent and reveal only a delayed hypersensitivity reaction
  

• Atopic dermatitis
  
• Eczema
  
• Dermatitis herpetiformis
  
• Papular urticaria
  
• Folliculitis
  
• Lichen planus
  
• Pruritic urticarial papules and plaques of pregnancy
  
• Adult linear IgA bullous dermatosis
  
• Syphilis
  
• Pediculosis
  
• Pityriasis rosea
  
• Impetigo
  
• Seborrheic dermatitis
  
• Flea bites and bedbugs
  

TREATMENT