Erythema nodosum / Behcet's disease

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Erythema nodosum
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In the majority of cases,
painful,
erythematous nodules
develop on the anterior surfaces of both legs,
that resolve without scarring over a two- to eight-week period.

Polyarthralgia, fever, and malaise frequently accompany the eruption.
erythrocyte sedimentation rate is often elevated.

antistreptolysin-O titer


Cause:
-------
streptococcal pharyngitis is the most common cause of erythema nodosum.
Erythema nodosum and hilar adenopathy: consider - sarcoidosis, TB, etc as the cause
oral contraceptives


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Behcet's disease
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clinical features:
---------------
oral ulcer / genital ulcer / erythema nodosum
uveitis / red eye

(unlike other erythema nodosum cases, Behcet's-associated lesions may ulcerate.)

Lab tests:
There is no lab test to confirm Becet's disease.
But exclude other conditions. In Becet's:
ANA is negative
RF is negative

{ 간단히

-ANA: neg
-RF: neg
}

Dx criteria:
International Study Group (ISG) criteria -
recurrent oral ulcer ( > 3 times a year ) plus one of the following:
-recurrent genital ulcer
-skin lesion (e.g. erythema nodosum)
-eye lesion (e.g. uveitis)
-positive pathergy test

(pathergy test: Pathergy is defined by a papule 2 mm or more in size developing 24 to 48 hours after oblique insertion of a 20 gauge

needle 5 mm into the skin, generally performed on the forearm.)

{ 간단히: muco- cutaneous + eye

-Oral
-Genital
-Skin
-Eye
}



Rx:
prednisone 1 mg/kg/day PO
azathioprine 2.5 mg/kg/day PO

corticosteroids can be tapered after active disease has been controlled.
immunosuppressants are continued for 1 year.

initial therapy: prednisone (40 to 60 mg PO daily) and azathioprine (50 mg PO daily). The prednisone dose is maintained at its initial

level for one month and then tapered off over three to four months. Azathioprine is increased as tolerated over four to six weeks to a

daily dose of 2.5 mg/kg.

{ 간단히

prednisone - 60 mg  for 1 month and then taper over 3 to 4 months
azathioprine - start with 50 mg. increase to 2.5 mg/kg over 1 month. continue for 1 year.
}


Complication:

CNS: impairment in - memory, speech, balance, etc
GIT: GIT ulcer, diarrhoea
Vessel: aneurysm (e.g. of major vessles including pulmonary vasculature -> hemoptysis.), large vessel arteritis, venous thrombosis