Rosen & Barkin's 5-Minute Emergency Medicine Consult (632 page)

Maintain universal precautions.

• No specific stabilization necessary
  
• ED is an important route for admission to the hospital and detecting infested patients early can be achieved by screening for high risk patients
  

• Treatment should not be empiric for patients with generalized itching but reserved for patients with a history of exposure, a typical eruption in a characteristic distribution, or both
  
• Treat patient and all persons in immediate contact with topical scabicide:
  
  • Treat all contacts at the same time, regardless of the presence of symptoms
    
• Permethrin 5% is 89–92% effective, and is well tolerated (category B pregnancy):
  
  • <2% of permethrin is absorbed into the skin, making its potential toxicity low:
    
    • For children ≥2 mo older
      
    • Massage from head to toe (avoid eyes and mouth) and remove in shower 8–14 hr later
      
    • Repeat 2nd application in 1–2 wk time
      
• Crotamiton 10% is 50–60% effective and used when other scabicides are not tolerated
  
• Ivermectin administered orally for 2 doses 7–14 days apart has shown similar efficacy as permethrin (but not used in pregnant or lactating women or children <15 kg):
  
  • Effective in patients unable to tolerate topical scabietics or in patients with resistant or crusted Norwegian scabies
    
  • May not be effective against all stages of life cycle (may not sterilize scabies eggs)
    
• Lindane 1% may be slightly less effective and is potentially toxic to the CNS:
  
  • Lindane absorption (through skin, lung or intestinal mucosa, or mucous membranes) is about 10%
    
  • Side effects include nausea, headache, vertigo, amblyopia, irritability, and seizure
    
  • Do not use in pediatric patients or patients with extensive excoriations or dermatitis
    
• Sulfur is the oldest known treatment of scabies, and is the drug of choice for infants <2 mo and for pregnant or lactating women
  
• Crusted Norwegian scabies 1st requires removal of hyperkeratotic scale with keratolytic to facilitate entry of the scabicide
  
• Treatment failures:
  
  • Treatment failures are frequent in crusted Norwegian scabies, and use of multiple agents including oral medications is often necessary
    
  • Machine wash and dry in hot cycles (60°C) or dry clean all clothes and bedding worn within 2 days of treatment or place items in plastic bags for 3 days
    
  • Vacuum household floors, carpets, mattresses, and furniture
    
  • Autoclaving, bleaching, or fumigation are not indicated
    
  • Emphasize that itching may continue for 1–4 wk after mites are killed due to skin inflammatory reaction
    
  • Topical steroids and oral antihistamines can reduce pruritic symptoms
    
  • Relapses can occur from untreated areas such as the scalp and subungual regions
    
  • Treatment failures tend to arise from poor patient understanding and inadequate patient education
    

• Scabicides:
  
  • Crotamiton 10% lotion or cream: Apply topically from neck down in adults and entire skin surface in children QHS for 2 nights, then rinse off 48 hr after last application
    
  • Ivermectin 3 mg tablets: 1st PO dose of 200 μg/kg should be followed by 2nd PO dose of 200 μg/kg 7–14 days later (pregnancy category C). Take with food
    
  • Lindane 1% lotion or cream: Apply topically from neck down and rinse off after 8–12 hr; contraindicated in infants, pregnancy, lactation, excessive excoriations, or seizure disorder
    
  • Permethrin 5% cream (Elimite): Apply topically from neck down in adults and entire skin in children QHS; rinse off after 8–14 hr (pregnancy class B, unknown safety in breast-feeding)
    
  • Sulfur 5–10% precipitated in petrolatum: Apply topically nightly for 3 consecutive nights and then wash off 24 hr later
    
• Antipruritics:
  
  • Low sedating/selective antihistamines:
    
    • Cetirizine (Zyrtec): Adults and peds >6 yr: 5–10 mg/d PO; 6–12 mo: 2.5 mg/d PO; 12–24 mo: 2.5 mg/d PO to BID; 2–6 yr: 2.5–5 mg/d PO
      
    • Fexofenadine (Allegra): Adult and peds >12 yr: 180 mg/d PO or 60 mg PO BID; 6 mo–5 yr: 15–30 mg PO BID; 6–11 yr: 30 mg PO BID
      
    • Loratadine (Claritin): Adults and peds >6 yr: 10 mg/d PO; 2–5 yr: 5 mg/d PO
      
  • Sedating/nonselective antihistamines:
    
    • Diphenhydramine (Benadryl): Adults and peds >12 yr: 25–50 mg PO q4–6h; 2–6 yr: 6.25 mg PO q4–6h; 6–12 yr: 12.5–25 mg PO q4–6h
      
    • Doxepin: 25–50 mg PO BID, peds: Dosing currently unavailable
      
    • Hydroxyzine HCl (Atarax): Adults and peds >12 yr: 25–100 mg PO q6–8h; <6 yr: 2 mg/kg/d PO div. q6–8h; 6–12 yr: 12.5–25 mg PO q6–8h
      

Permethrin 5% cream

PO Ivermectin or Crotamiton 10% lotion or cream

FOLLOW-UP

• Patients with severe topical or systemic super infection
  
• Refractory or relapsing cases
  

Nontoxic appearing patients with routine symptoms

Re-evaluate after 1–4 wk for recurrence:

• Itching may persist for up to 4 wk after correctly applied therapy
  
• Treatment failure is often due to incorrect application of topical agents or due to failure to treat all contacts
  
• Retreat if live mites are found
  

• Scabies is a common parasitic infection that is transmitted by prolonged direct skin-to-skin contact
  
• Scabies in children can differ from that in adults
  
• Crusted Norwegian scabies is characterized by a large number of mites, and is seen in immunocompromised or institutionalized patients
  
• Treatment failure is common:
  
  • Proper patient education can decrease treatment failures.
    

• Chosidow O. Clinical practices. Scabies.
  N Engl J Med.
  2006;354:1718–1727.
  
• Currie BJ, McCarthy JS. Permethrin and ivermectin for scabies.
  N Engl J Med.
  2010;362:717–725.
  
• Hong MY, Lee CC, Chuang MC, et al. Factors related to missed diagnosis of incidental scabies infestations in patients admitted through the emergency department to inpatient services.
  Acad Emerg Med
  . 2010;17:958–964.
  
• Leone PA. Scabies and pediculosis pubis: An update of treatment regimens and general review.
  Clin Infect Dis
  . 2007;44(suppl 3):S153–S159.
  
• Scabies. Atlanta: Centers for Disease Control and Prevention, 2008. Accessed at
  http://www.cdc.gov/scabies/
  .
  
• Strong M, Johnstone P. Interventions for treating scabies.
  Cochrane Database Syst Rev
  . 2007;(3):CD000320.
  

See Also (Topic, Algorithm, Electronic Media Element)

• Pediculosis
  
• Pityriasis rosea
  

CODES

133.0 Scabies

BASICS

• The scaphoid is the most commonly fractured carpal bone.
  
• This bone is the stabilizer between the distal and proximal carpal rows.
  
• Injury may result in arthritis, avascular necrosis, or malunion.
  
• Classified as:
  
  • Proximal 3rd (10–20%)
    
  • Middle 3rd (the waist, 70–80%)
    
  • Distal 3rd (the tuberosity)
    
  • Tubercle fractures
    
• Fractures are missed on initial radiographs 10–15% of the time, and delayed diagnosis greatly increases risk of complications.
  
• The blood supply to the scaphoid enters distally
  
• The more proximal the fracture, the higher the likelihood for avascular necrosis
  
• As the wrist is forcibly hyperextended, the volar aspect of the scaphoid fails in tension and the dorsal aspect fails in compression resulting in a fracture.
  

Generally results from a fall on an outstretched (dorsiflexed) hand (FOOSH injury).

DIAGNOSIS

FOOSH injury

• Maximal pain and tenderness in the anatomic snuffbox (may be elicited with direct palpation or axial loading of the thumb); 90% sensitive, 40% specificity.
  
• Dorsal wrist pain distal to the radial styloid and decreased range of motion of the wrist and thumb
  
• Rarely, incidental damage to the superficial branches of the radial nerve results in sensory changes.
  
• Palpate the scaphoid tubercle for tenderness by radially deviating the wrist and palpating over the palmar aspect of the scaphoid; 87% sensitivity, 57% specificity.