see also: Parotid Sarcoidosis; Salivary Swelling

Definitions

1. Heerfordt's syndrome = "uveoparotid fever" - sarcoidosis manifest as unilateral facial nerve palsies and is characterized by parotid gland enlargement, fever, uveitis, and cranial nerve palsies.
2. Löfgren's syndrome (especially in Caucasians): erythema nodosum, fever, arthralgias, and radiographic evidence of bilateral hilar adenopathy - likely Sarcoidosis (Parrish 2009)

Genetics of Sarcoidosis (Muller-Quernheim 2008)

1. Differences in prevalence and incidence between ethnic groups and races as well as clusters of cases in families supports genetic contribution to the disease
2. Lifetime risk of sarcoidosis by race (Rybicki 1997):
   1. African-American: 2.4%
   2. Causcasians in U.S.: 0.85%
3. Clinical presentation varies between ethnic groups

Diagnosis

1. Diagnosis of exclusion - relies on clinical/radiographic/histopath examination
2. Radiographic
   1. Chest radiography in all cases
   2. PET and gallium scanning of questionable value - may useful in specfic cases
   3. Other imaging studies based on organ involvement
3. Tissue biopsy
   1. Noncaseating granulomas
   2. If positive for noncaseating granuloma
      1. Further w/u requires recognition that sarcoidosis is a systemic disease
      2. In addition to organ-involvment consultations, needs cardiac and opthalmologic w/u
4. Lab
   1. serum calcium
      1. 10% of patients with sarcoidosis will have at least transient hypercalcemia; hypercalciuria more common (Parrish 2009)
      2. macrophages in patients with sarcoidosis are capable of the hydroxylation that produces the active metabolite of vitamin D which is the likely causative factor for hypercalcemia (Sharma 1996)
   2. urinalysis
   3. liver enzymes
   4. CBC
   5. SACE (serum angiotensin converting enzyme) (Parrish 2009)
      1. At one point thought to be diagnostic of sarcoidosis
      2. Epithelioid cells of sarcoid granulomas produce serum angiotensin converting enzyme
      3. Not thought to be sensitive/specific enough to be used as diagnostic tool
      4. SACE also elevated:  diabetes mellitus, cirrhosis, acute hepatitis, chronic renal disease, silicosis, Gaucher's disease, leprosy, asbestosis, and berylliosis

References

Parrish S and Turner JF: "Diagnosis of Sarcoidosis"  Disease a Month Vol 55 Issue 11  2009

Sharma O.P.:  Vitamin D, calcium, and sarcoidosis.  Chest 109. 535-539.1996; 

Muller-Quernheim J, Schurmann M, Hoffmann S, Gaede KI, Fischer A, Prasse A, Zissel G, and Schreiber S: Genetics of Sarcoidosis. Clinics in Chest Medicine Vol 29, Issue 3 (Sept 2008)

Rybicki B.A., Major M., Popovich , Jr , JrJ., et al:  Racial differences in sarcoidosis incidence: a 5-year study in health maintenance organization.  Am J Epidemiol 145. 234-241.1997;