Inflammation of the thyroid (thyroiditis) may be associated with a wide range of causes. These include a thyroiditis that occurs as part of a systemic viral infection.
The term de Quervain's thyroiditis may be used for a self-limited thyroiditis associated with a viral infection. It also describes a granulomatous thyroiditis with giant cells (giant cell thyroiditis).
Features:
(1) The patient has evidence of a viral infection.
(2) The patient develops enlargement of the thyroid gland, which may be painful or painless.
(3) There may variable changes in circulating thyroid hormones, including transient thyrotoxicosis.
(4) A thyroid scan may show decreased uptake.
(5) Serum levels of C-reactive protein and erythrocyte sedimentation rate (ESR) may be elevated.
(6) The thyroiditis resolves as the infection clears.
(7) Other explanations for thyroiditis are excluded.
Viruses implicated with thyroiditis include:
(1) dengue
(2) influenza
(3) cytomegalovirus
(4) Coxsackievirus and other enteroviruses
(5) viral hepatitis A, B, C or E
(6) mumps
(7) Epstein-Barr virus (EBV)
(8) measles
(9) chickenpox
(10) rubella
(11) human foamy virus
(12) parvovirus B19
(13) HSV-1
(14) HTLV-I
(15) HIV
(16) SARS coronavirus
(17) rubella
(18) polyomavirus (SV40)
Differential diagnosis:
(1) concurrent thyroiditis and viral infection that occur independent of each other
(2) autoimmune thyroiditis triggered by the viral thyroiditis
