Postpartum thyroiditis differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Furqan M M. M.B.B.S[2]Sunny Kumar MD [3]

Overview

Postpartum thyroiditis must be differentiated from other causes of thyroiditis, such as De Quervain's thyroiditis, Hashimoto's thyroiditis, Riedel's thyroiditis, and suppurative thyroiditis. Postpartum thyroiditis must also be differentiated from other diseases which cause hypothyroidism. As postpartum thyroiditis may cause transient thyrotoxic symptoms, the diseases causing thyrotoxicosis must also be considered in the differential diagnosis.

Differentiating Postpartum Thyroiditis from other Diseases

Differentiating postpartum thyroiditis from other causes of thyroiditis

• Postpartum thyroiditis must be differentiated from other causes of thyroiditis, such as De Quervain's thyroiditis, Hashimoto's thyroiditis, Riedel's thyroiditis, and suppurative thyroiditis.

Conditions	Causes	Age of onset (years)	Pathological findings	Diagnostic approach
Hashimoto's thyroiditis	Autoimmune	All ages, peak at 30-50	Lymphocytic infiltration Germinal centers Fibrosis (in some variants)	Increased TSH (hypothyroidism) TPO antibodies present in high titer I-123 uptake usually decreased
Painful subacute (De Quervain's) thyroiditis	Unknown	20-60	Giant cells Granulomas	Increased TSH (hypothyroidism) and/or Decreased TSH (thyrotoxicosis) TPO antibodies absent or very low titer I-123 uptake decreased
Silent thyroiditis	Autoimmune	All ages, peak at 30-40	Lymphocytic infiltration Lymphoid follicles	Increased TSH (hypothyroidism) and/or Decreased TSH (transient hypothyroidism) TPO antibodies present in high titer I-123 uptake usually decreased
Postpartum thyroiditis	Autoimmune	Childbearing age	Lymphocytic infiltration	Increased TSH (hypothyroidism) and/or Decreased TSH (transient hypothyroidism) TPO antibodies present in high titer I-123 uptake usually decreased
Riedel's thyroiditis	Unknown	30-60	Dense fibrosis	Normal TSH (euthyroidism) TPO antibodies usually present I-123 uptake decreased or normal
Suppurative thyroiditis	Infection	Children, 20-40	Abscess formation	Normal TSH (euthyroidism) TPO antibodies absent I-123 uptake normal

Differentiating postpartum thyroiditis from other causes of hypothyroidism

• Postpartum thyroiditis must be differentiated from other causes of hypothyroidism on the basis of history and symptoms and laboratory findings:

Disease		History and symptoms		Laboratory findings							Additional findings
		Fever	Pain	TSH	Free T4	T3	T3RU†	Thyroglobin	TRH	TPOAb^
Primary hypothyroidism	Autoimmune (Hashimoto's thyroiditis)	-	-	↑*	↓	Normal/↓	Normal/↓	Normal/↑	Normal	Present (high titer)	May be accompanied by other autoimmune diseases
	Riedel's thyroiditis	-	-	Normal/↑	Normal/↓	Normal/↓	Normal/↓	Normal	Normal	Usually present	Riedel's thyroiditis usually presents with hard and fixed thyroid mass.
	Infectious thyroiditis	+	+	Normal	Normal	Normal	Normal	Normal	Normal	Absent	Infectious thyroiditis associated with neck pain
Transient hypothyroidism	Subacute (de Quervain's) thyroiditis	+/-	+/-	↑/↓	↓/↑	Normal	↓	↑	Normal	Low/absent	May present primarily with hyperthyroidism
	Postpartum thyroiditis	+/-	+/-	↑/↓	↓/↑	Normal	↓	↑	Normal/↑	Present (high titer)	May present primarily with hyperthyroidism
	Silent thyroiditis	-	-	↑/↓	↓/↑	Normal	↓	↑	Normal	Present (high titer)	May present primarily with hyperthyroidism
Others	Drug-induced	-	-	↑/↓	↓/↑	Normal	↓	Normal/↑	Normal	Absent**	History of hyperthyroidism History of trauma History of drug use, surgery, or radiation
	Radiation-induced
	Trauma induced
	Radioiodine induced
	Thyroidectomy
	Subclinical hypothyroidism	-	-	↑	Normal	Normal	Normal	Normal	Normal	Normal/↑	Asymptomatic

(†)T3RU; Triiodothyronine Resin uptake. (^)TPOAb; Thyroid peroxidase antibodies. (*)TSH may be decreased transiently in the thyrotoxicosis. (**)TPOAb may be present in drug-induced hypothyroidism or hyperthyroidism such as Interferon-alpha, interleukin-2, and lithium.

Differentiating postpartum thyroiditis from other causes of thyrotoxicosis

• Postpartum thyroiditis can initially present with thyrotoxicosis which must be differentiated from other causes of thyrotoxicosis.

Disease		History and symptoms		Laboratory findings								Additional findings
		Fever	Pain	TSH	Free T4	T3	T3RU†	Thyroglobin	TRH	TSH Receptor Antibody	TPOAb^
Thyroiditis	Postpartum thyroiditis	+/-	+/-	↑/↓	↓/↑	Normal	↓	↑	Normal/↑	Absent	Present (high titer)	May present with hypothyroidism
	Hashimoto's thyroiditis (Hashitoxicosis)	-	-	↑*	↓	Normal/↓	Normal/↓	Normal/↑	Normal	Absent	Present (high titer)	May be accompanied by other autoimmune diseases
	Subacute (de Quervain's) thyroiditis	+/-	+/-	↑/↓	↓/↑	Normal	↓	↑	Normal	Absent	Low/absent	May present with hypothyroidism
	Silent thyroiditis	-	-	↑/↓	↓/↑	Normal	↓	↑	Normal	Absent	Present (high titer)	May present with hypothyroidism
Primary hyperthyroidism	Grave's disease	-	-	↓	↑	Normal/↑	↑	↑	Normal	Present	Absent	Opthalmopathy and dermopathy may be present
	Toxic thyroid nodule	-	-	↓	↑	Normal/↑	↑(hot nodule)	Normal/↑	Normal	Absent	Absent	-
Secondary hyperthyroidism	Pituitary adenoma	-	-	↑	↑	Normal/↑	↑	Normal/↑	Normal	Absent	Absent	Inappropriately normal or increased TSH
Tertiary hyperthyroidism	Tertiary hyperthyroidism	-	-	↑	↑	↑	↑	Normal/↑	↑	Absent	Absent	Inappropriately normal or increased TSH
Drug induced	Amiodarone type 1	-	-	↓	↑	Normal/↑	↓	Normal/↑	Normal	Absent	Absent	High urinary iodine
	Amiodarone type 2	-	-	↓	↑	Normal/↑	Absent/↓	Normal/↑	Normal	Absent	Absent	High urinary iodine
Others	Factitious thyrotoxicosis	-	-	↓	↑	Normal/↑	↓	↓	Normal	Absent	Absent	Decreased thyroglobulin
	Trophoblastic disease	-	-	↓	↑	Normal/↑	↑	-	Normal	Absent	Absent	-
	Struma ovarii	-	-	↓	↑	Normal/↑	↓	-	Normal	Absent	Absent	-

(†)T3RU; Triiodothyronine Resin uptake. (^)TPOAb; Thyroid peroxidase antibodies.

Differentiating various diseases on the basis of type of thyroid dysfunction

Stages	Peek presenting purpural month	Disease	Symptoms and Signs				Labs							Mechanisum
			Fatiuge	Neck swelling	Low mood	Irritability	TSH	FT4	TPO ab	ESR	RAI U	Thyroid U/S	Microscopic Picture
Persistent hyperthyroidism	4-6	Grave's disease	+	Small painful mass	+	+ Early	↓	↑↑	Neg	↑	↑	Diffusely enlarged hypervascular heterogeneous echotexture	hyperplastic follicles due to eosinophilic cytoplasm scalloping	TSHR activating antibodies
Transient hyperthyroidism	2-4	Silent thyroiditis	+	Small painless goiter	+ Late	+ Early	NL or ↓	↑↑	50%	NL	↓	Markedly decreased vascularity variable heterogeneous texture	Lymphocytic infiltration & follicles	CD4 T-cell activation mutation
		Postpartum thyroiditis	+	Small painless goiter	+ Late	+ Early	NL or ↓	↑↑	>80%	↑	↓	Hypoechoic diffusely enlarged with normal or decreased vascularity	Lymphocytic infiltration & follicles	Reg T-cell gain in function mutation
		Subacute (de Quervain's) granulomatous thyroiditis	+	Small painful mass	+ late	+ early	nl or ↓	↑↑	neg	↑	↓	Diffusely enlarged & normal or decreased  vascularity	Giant cells granulomas	Systemic viral infections
		Factitious thyrotoxicosis	+	Nl	Neg	+ Early	NL or ↓	↑↑	Neg	NL	↓	NL	Normal histology	Thyroixine intake
		Acute suppurative thyroiditis	+	Small painful mass	+ Late	+ Early	NL or ↓	↑↑	Neg	↑	↓	Variable heterogeneous texture perithyroidal hypoechoic space due to abscess	Polymorphonuclear leukocytes lymphocytes exudates	Viral, Bacterial
Destructive hyperthyroidism	4-6	Subacute (de Quervain's) granulomatous thyroiditis	+	Small painful mass	+ Late	+ Early	NL or ↓	↑↑	Neg	↑	↓	Diffusely enlarged & normal or decreased  vascularity	Gaint cells granulomas	Systemic viral infections
		Postpartum thyroiditis	+	Small painless goiter	+ Late	+ Early	NL or ↓	↑↑	>80%	↑	↓	Hypoechoic diffusely enlarged& normal or decreased vascularity	Lymphocytic infiltration & follicles	Reg T-cell gain in function mutation
		Acute suppurative thyroiditis	+	Small painful mass	+ Late	+ Early	NL or ↓	↑↑	neg	↑	↓	Variable heterogeneous texture perithyroidal hypoechoic space due to abscess	Polymorphonuclear leukocytes lymphocytes exudates	Viral, Bacterial
Transient hypothyroidism	2-4	Postpartum thyroiditis	+	Small painless goiter	+ Late	+ Early	NL or ↑	↓	>80%	↑	↓	Hypoechoic diffusely enlarged & normal or decreased vasclarity	Lymphocytic infiltration & follicles	Reg T-cell gain in function mutation
		Silent thyroiditis	+	Small painless goiter	+ Late	+ Early	NL or ↑	↓	+	NL	↓	Markedly decreased vascularity variable heterogeneous texture	Lymphocytic infiltration & follicles	CD4 T-cell activation mutation
		Subacute (de Quervain's) granulomatous thyroiditis	+	Small painful mass	+ Late	+ Early	NL or ↑	↓	Neg	↑	↓	Diffusely enlarged normal or decreased  vasclarity	Giant cells & granulomas	Systemic viral infections
		Acute suppurative thyroiditis	+	Small painful mass	+ Late	+ Early	NL or ↑	↓	Neg	↑	↓	Variable heterogeneous texture perithyroidal hypoechoic space due to abcess	Polymorphonuclear leukocytes lymphocytes exudates	Infections viral,bacterial
Persistent hypothyroidism	6	Riedel's thyroiditis	+	Small painful mass	+ Late	+ Early	↑	↓	75%	↑	↓	Homogeneously hypoechoic fibrotic invasion of the adjacent structures	Lymphocytes, plasma cells, and eosinophils in a dense matrix of hyalinized connective tissue	Viral Bacterial
		Postpartum thyroiditis	+	Small painless goiter	+ Late	+ Early	↑	↓	>80%	↑	↓	Hypoechoic diffusely enlarged& normal or decreased vasclarity	Variable heterogeneous texture, hypoechogenic	Reg T-cell gain in function mutation
		Hashimoto's thyroiditis	+	Painful mass	+ Late	+ Early	↑	↓	95%	↑	↓	Heterogeneous echotexture decreased vasclarity hypoechoic micronodules	Lymphoid follicles germinal centers Hurthle cells	Reg T-cell dysfunction
		Acute suppurative thyroiditis	+	Small painful mass	+ Late	+ Early	↑	↓	Neg	↑	↓	Variable heterogeneous texture perithyroidal hypoechoic space due to abcess	Polymorphonuclear leukocytes lymphocytes exudates	Systemic viral infections