<unk> , is also known as subacute lymphocytic thyroiditis.<unk>  is a type of resolving thyroiditis, which also includes postpartum thyroiditis.<unk>  was first described as the painless form of the subacute thyroiditis as the clinical course is same. It was differentiated from postpartum thyroiditis on the basis of thyroid involvement outside of the postpartum period. The exact pathogenesis of<unk>  is not fully understood. It is thought that<unk>  is the result of an autoimmune phenomenon. Activated matured T-cells (HLA-DR+CD3+), activated helper/inducer T-cells (HLA-DR+CD4+), activated suppressor, and cytotoxic T-cells (HLA-DR+CD8+) were higher in patients with<unk>  as compared to the healthy controls. It indicates that the activation of T cells, especially of helper/inducer T cells, might have an important role in the pathogenesis of<unk> .<unk>  is associated with the HLA-DR3 and DR5 genes. Lymphocytic infiltration of the thyroid gland, the absence of Hurthle cells and germinal centers on histological analysis are the microscopic histopathological findings suggestive of<unk> .<unk>  may be caused by the activation of helper T cells and cytotoxic T cells, genetic factors, and autoimmune antibodies.<unk>  is a rare disease with the incidence of up to 23000 per 100,000 individuals with hyperthyroidism. The prevalence of<unk>  is approximately 1000 per 100,000 individuals with thyrotoxicosis.<unk>  commonly affects patients in 30-40 years of age. Females are more commonly affected by<unk>  than males. The female to male ratio is approximately 4 to 1.<unk>  is more common in areas of higher dietary iodine intake. Common risk factors in the development of<unk>  include lithium, radiation therapy in Hodgkin's lymphoma, cessation of corticosteroids in Cushing's syndrome (post adrenalectomy), and certain autoimmune conditions.<unk>  presents with the symptoms of thyrotoxicosis. It further leads to a euthyroid phase and eventually hypothyroid phase before the complete resolution of the disease. Complications may include hypothyroidism. There are no established criteria for the diagnosis of<unk> . Decreased radioactive iodine uptake, elevated serum T3, and T4 are helpful in diagnosing<unk> . Histopathology is also important to differentiate<unk>  from other forms of thyroiditis. Patients with<unk>  usually appear fatigued and restless. Patients with<unk>  may have the history of other autoimmune diseases such as SLE, immune thrombocytopenic purpura (ITP), and lymphocytic hypophysitis. The most common symptoms of<unk>  are palpitations, tachycardia, nervousness, and tremors. Physical examination of patients with<unk>  is usually remarkable for tachycardia and palpitations. In the recovery phase of<unk> , the patient may show signs of hypothyroidism. Laboratory findings consistent with the diagnosis of<unk>  usually include increased free T3, free T4, decreased thyroid<unk> imulating hormone in thyrotoxicosis and decreased free T3, free T4, increased thyroid<unk> imulating hormone in hypothyroidism. Anti-thyroid peroxidase antibody is usually high. The most common EKG finding associated with the thyrotoxicosis in<unk>  is sinus tachycardia. Rarely signs of myocardial damage, including<unk>  segment elevation and arrhythmias, can also be seen in thyrotoxicosis. MRI is not used in the diagnosis of<unk> . However, diffusion-weighted MRI shows low apparent diffusion coefficient (ADC). 24-hour iodine-123 uptake is decreased in<unk> . The histological analysis in<unk>  may show the infiltration of inflammatory cells, lymphoid follicles, and loss of the follicular integrity. Fine needle aspiration cytology helps to differentiate between the benign and malignant nodules. Pharmacologic medical therapies for<unk>  include beta blockers for thyrotoxicosis symptoms and levothyroxine for the hypothyroidism if it follows the hyperthyroid<unk> ate. Surgical intervention is not usually recommended for the management of<unk> .Thyroidectomy is considered only when there are repeated relapses despite appropriate treatment.
Silent thyroiditis
Hashimoto's thyroiditis
Toxic multinodular goiter
Riedel's thyroiditis
Postpartum thyroiditis
Nodular thyroid disease
Follicular thyroid cancer
Thyroid adenoma