Description

Temporal (Giant Cell) Arteritis can be diagnosed using a classification tree approach.


top level

second level

third level

fourth level

diagnosis

clinically abnormal temporal arteries

age at onset >= 50 years

 

 

TA

 

age at onset < 50 years

 

 

non-TA

clinically normal temporal arteries

artery biopsy positive

age at onset >= 50 years

 

TA

 

 

age at onset < 50 years

 

non-TA

 

artery biopsy negative

claudication present

age at onset >= 50 years

TA

 

 

 

age at onset < 50 years

non-TA

 

 

claudication absent

 

non-TA

 

Surrogate criteria:

(1) If the clinical status of the temporal arteries is unknown, then the presence or absence of a tender scalp or scalp nodules may be used.

(2) If an artery biopsy is not available, then the presence or absence of a new headache may be used.

 

 

Criteria

Comment

age at disease onset >= 50 years

Occurs only rarely before the age of 50.

new headache

new onset or new type of localized pain in the head

temporal artery abnormality

temporal artery tenderness to palpation, or decreased pulsation, unrelated to arteriosclerosis of cervical arteries

claudication of jaw, tongue or on deglution

development or worsening of fatigue or discomfort in muscles of mastication, tongue or swallowing muscles while eating

abnormal temporal artery biopsy

Artery shows vasculitis with predominance of mononuclear cell infiltration or granulomatous inflammation, usually with multinucleated giant cells. The involvement is segmental, so an adequate biopsy is needed for diagnosis.

scalp tenderness or nodules

development of tender areas or nodules over the scalp, away from the temporal artery or other cranial arteries

 

 

Patient Subsets

Findings

TA patients

age >= 50 years at onset; clinically abnormal temporal arteries

 

age >= 50 years at onset; artery biopsy positive; clinically normal temporal arteries

 

age >= 50 years at onset; claudication; clinically normal temporal arteries; artery biopsy negative

non-TA patients

clinically normal temporal arteries; negative artery biopsy; no claudication

 

age < 50 years at onset; claudication present; clinically normal temporal arteries; negative artery biopsy

 

age < 50 years at onset; clinically normal temporal arteries; positive artery biopsy

 

age < 50 years at onset; clinically abnormal temporal arteries

 

Performance:

• The sensitivity 95.3% and specificity 90.7%

 


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