Tag Archives: rheum

biphasic allergic reactions…

26 Jan

…are RARE.

via this recent ACEP Now article by Dr. Milne

SHORTCUT NUMBERS:

data from 2 urban ED’s over 5 yrs

~2300 allergic reactions + ~500 anaphylaxis cases

185 returned for 2nd visit

5 (0.18% of ~2800 allergic rxns) were clinically important biphasic reactions

  • 2 were during the initial ED visit
  • 3 were post-discharge (at 28, 35, and 143 hrs s/p)
  • no fatalities

 

THEIR BOTTOM LINE:

Prolonged observation is likely unnecessary in patients whose symptoms resolve with therapy in the ED. Biphasic reactions are rare and can occur anywhere from 10 minutes up to six days after an initial reaction.”

 

Food for thought.

 

References: ACEP Now article; picture

 

how useful is temple percussion for temporal arteritis?

21 Nov

QUICK PEARLS:

prevalence of TA in the general population is less than 1%

American College of Rheumatology classification criteria (need 3/5):

  • temporal artery tenderness or decreased temporal artery pulse
  • new headache,
  • onset at > 50 years old
  • erythrocyte sedimentation rate > 50 in first hr
  • positive temporal artery biopsy.

 

 

analysis of 21 studies with temporal artery biopsies

  • 2 historical features that substantially increased the likelihood of TA among patients referred for biopsy
    • jaw claudication (positive LR, 4.2; 95% CI, 2.8-6.2)
    • diplopia (positive LR, 3.4; 95% CI, 1.3-8.6).
  • absence of any temporal artery abnormality was the only clinical factor that modestly reduced the likelihood of disease (negative LR, 0.53; 95% CI, 0.38-0.75).
  • Predictive physical findings included
    • temporal artery beading (positive LR, 4.6; 95% CI, 1.1-18.4),
    • prominence (positive LR, 4.3; 95% CI, 2.1-8.9),
    • tenderness (positive LR, 2.6; 95% CI, 1.9-3.7).

 

retrospective chart review of 98 incident cases of GCA (giant cell arteritis)

  • of the 25 (out of 98) with a clinically abnormal temporal artery (e.g. tenderness)
    • 22 (88%) were biopsy-positive
    • 3 (12%) were biopsy negative
  • of the 73 (out of 98) with a clinically normal temporal artery
    • 46 (63%) were biopsy-positive
    • 27 (37%) were biopsy negative

 

BOTTOM LINE:

how useful is temporal artery percussion?  not that great, but it’s part of the puzzle (and the ACR criteria), so it may increase the likelihood of the diagnosis.  just don’t rely on it in isolation.

 

References: JAMA article; Thierry Zenone and Marie Puget Sensitivity of clinically abnormal temporal artery in giant cell arteritis International Journal of Rheumatic Diseases 16; picture 1, picture 2

Anaphylaxis: pearls

25 Mar

Some highlights from a good article by Dr. James Roberts over at EM News:

 

FINDINGS IN ANAPHYLAXIS (many are probably less than you thought):

  • generalized erythema 66%
  • pruritis 56%
  • urticaria 50%
  • dyspnea 43%
  • angioedema 40%
  • wheeze 35%
  • laryngeal edema 25%
  • bronchospasm 18%
  • syncope/dizziness 15%
  • BP <90 mmHg 9%

 

good evidence for epinephrine in anaphylaxis

IM better than SC; “important to avoid the use of IV epi in all but the most egregious cases” (if you do go IV, 1:10,000 concentration, and slowly–60-90 sec diluted in saline)

“no report of problems or worse outcome when epinephrine was used…in patients with cardiac history” (anaphylaxis is bad anyways)

not much evidence for pre-medication with glucocorticoids or H1/H2-blockers preventing anaphylactoid reactions to contrast media (“Such premedication will likely persist.”)

for anaphylaxis treatment, “I see no downside to giving glucocorticoids or antihistamines…but the first drug chosen should always be epinephrine.”

reminder: standard dose is 0.3mg (1:1000 concentration) IM

 

References: EMN article; picture

 

ice pack test in myasthenia gravis

8 Aug

Myasthenia gravis

Autoimmune disease

Acetylcholine receptor antibodies are antagonists at the neuromuscular junction.

 

presenting symptoms

  • weakness and fatigue after repetitive use of voluntary muscles.
  • Ptosis and diplopia are the most common
  • limb weakness or oropharyngeal symptoms
  • Life threatening myasthenia crisis respiratory failure can be seen before diagnosis or due to inadequate drug therapy or tolerance.

 

TESTING:

ACH-R antibody testing is the most specific test, although 15% can have false negatives.

quick test: placing an ice pack over the effected eye and see if symptoms improve.

Improvement of symptoms in 2 minutes is positive for myasthenia gravis.

 

HOW DOES THIS WORK?

by cooling the tissues, and more specifically the skeletal muscle fibers, the activity of the acetylcholinesterases are inhibited and there is enough acetocholine to fire the muscle fibers and contract.

 

Submitted by C. Stokes.

 

References: Kearsey C, et al. The use of the ice pack test in myasthenia gravis. Journal of the Royal Society of Medicine Short Reports. 2010 June; 1(1): 14.; picture

Transverse myelitis: quick hits

25 Jul

BASICS

segmental spinal cord injury caused by acute inflammation

RARE (1-5 cases per million)

Most are idiopathic, presumably result from an autoimmune process

up to half have a preceding infection

can also occur in multiple sclerosis (MS) and can be the presenting demyelinating event

also associated with connective tissue diseases (e.g. lupus, Sjogren’s, scleroderma, RA, etc).

 

inflammation of TM is generally restricted to one or two segments, usually in the thoracic cord.

 

SYMPTOMS:

Symptoms typically develop rapidly over several hours (~37 percent worsen maximally within 24 hours)

Typically bilateral, producing weakness and sensory disturbance below the level

 

In addition to diminished sensation, pain and tingling are common and frequently include a tight banding or girdle-like sensation around the trunk, which may be very sensitive to touch.

Back and radicular pain are also common.

Bowel and bladder dysfunction, reflective of autonomic involvement, also occur.

 

Diagnosis:

MRI

Cerebrospinal fluid (CSF)

  • elevated protein level (usually 100 to 120 mg/100 mL)
  • moderate lymphocytosis (usually <100 /mm3).
  • Glucose levels are normal.
  • Oligoclonal bands are usually not present in isolated TM, and when present suggest a higher risk of subsequent MS.

 

TREATMENT OPTIONS:

often treated with corticosteroids, though there is limited evidence

other immunosuppressive drugs

 

Most patients have at least a partial recovery, after 1-3 months

Some degree of persistent disability is common (~ 40%)

Significant recovery is unlikely if there is no improvement by three months.

a small percentage may suffer a recurrence.

 

Submitted by J. Stanton.

 

References: uptodate.com; picture

Kawasaki Disease (30-second review)

20 Jun

Sensitivity of physical exam findings:

Fever x 5 days plus at least 4/5 of:

1. Conjunctival injection (bilateral)

2. MM changes (eg. Fissured lips, strawberry tongue)

3. Polymorphous rash

4. Extremity changes (edema, desquamation)

5. Cervical LAD

 Sensitivity 90%, specificity 54%

 

20-25% develop coronary aneurysms, typically clinically silent until sudden death

 

IVIG reduces aneurysms to only 2-4% cases

 

MIMICKERS – GAS pharyngitis (scarlet fever), measles

 

Med-school mnemonic: CRASH & BURN

  • Conjunctivitis
  • Rash
  • Adenopathy/Aneurysm
  • Strawberry tongue
  • Hand/foot induration/desquamation

&

  • BURN – fever x 5 days

 

 

Submitted by J. Andrick.

 

References: Kawasaki Syndrome, Burns, Glode review Lancet 2004; Kawasaki Disease II Yim et al. J Ped Child Health.; picture

Lyme Disease – ‘tis the season!

6 Jun

Tick-borne illness caused by the spirochete Borrelia burgdorferi

 

3 clinical stages

–    Stage 1, early localized disease (days-weeks):

  • target lesion of erythema migrans (EM) -> occurs at the site of the tick bite. Near the axilla, inguinal region most common. 

lyme

 

  • nonspecific viral prodrome -> fatigue, anorexia, headache, neck stiffness, myalgias, arthralgias, regional lymphadenopathy, fever. Note: upper respiratory and GI symptoms uncommon.

 

–     Stage 2, early disseminated disease (weeks-months) :

  • multiple EM lesions
  • +/- cardiac -> heart block,cardiomyopathy
  • +/- neurologic -> lymphocytic meningitis, cranial nerve palsies (especially of the facial nerve), radiculopathy, peripheral neuropathy, mononeuropathy multiplex

 

–     Stage 3, late disease (months-years):

  • arthritis of one or few large joints
  • +/- neurologic -> different from the stage two findings such as subtle cognitive disturbance, chronic axonal polyneuropathy (spinal radicular pain or distal parasthesias)

 

 CDC criteria for diagnosis of Lyme Disease

–     presence of EM OR one late manifestation plus laboratory confirmation of infection (IgM or IgG antibodies to b. burgdorferi in serum or CSF)

 

Treatment

It’s complicated, but the basic idea is doxycycline 100 mg PO bid x 10-21 days for erythema migrans (stage 1). This treatment lengthens to 21-28 days for neurologic, cardiac, or musculoskeletal involvement (stage 2-3). Second line is amoxicillin or cefuroxime.

 

Submitted by K. Estes.

 

References: Steere AC. Lyme disease. N Engl J Med 2001; 345:115.; Centers for Disease Control and Prevention. Case definitions for infectious conditions under public health surveillance. MMWR Morb Mortal Recomm Rep 1997;46(RR-10):1.; Wormser GP, Dattwyler RJ, Shapiro ED, et al. The Clinical Assessment, Treatment, and Prevention of Lyme disease, Human Granulocytic Anaplasmosis, and Babesiosis: Clinical Practice Guidelines by the Infectious Diseases Society of America. Clin Infect Dis 2006; 43:1089.