Is Graves' dermopathy a generalized disorder?

Clinical Profiles of Thyroid Dermopathy: A Dermato-Endocrinological Perspective

Thyroid disorders sometimes have extra-thyroidal manifestations. Hyperthyroidism is a clinical syndrome resulting from excessive secretion of thyroid hormones. The most common cause is Graves’ disease. About 0.5–4.3% of patients with Graves’ disease have an infiltrative dermopathy called thyroid dermopathy, which is due to excessive deposition of glycosaminoglycans from activated fibroblasts. Skin fibroblasts are activated by thyroid stimulating hormone receptor antibodies the whole process being initiated by T lymphocytes. Rarely, thyroid dermopathy is also found in other thyroid disorders such as Hashimoto thyroiditis. The diffuse non-pitting edema variant is the most common clinical presentation. Other variants include the nodular, plaque, mixed, and elephantiasis types. Usually, the main concerns of the patients are cosmetic, discomfort, and difficulty in wearing shoes. Thyroid dermopathy usually presents after the diagnosis of Graves’ disease, but it may also present together or sometime after this condition. Rarely, thyroid dermopathy presents before the diagnosis of Graves’ disease is made. Apart from the shin and feet, other sites that can be affected include the arms, forearms, back, thighs, pinna, and nose. The management is multidisciplinary, involving dermatologists and endocrinologists. Usually, controlling the thyroid dysfunction does not translate into regression of the skin lesions. However, many patients have their thyroid dermopathy regress spontaneously, while others usually require local therapy. Other therapeutic options include systemic therapy such as pentoxifylline, compressive physiotherapy, and surgery.

Thyrotoxic Valvulopathy: Case Report and Review of the Literature

We report a 42-year-old female who was admitted for abdominal pain, and also endorsed dyspnea, fatigue and chronic palpitations. Past medical history included asthma, patent ductus arteriosus repaired in childhood and ill-defined thyroid disease. Physical examination revealed blood pressure of 136/88 mm Hg and heart rate of 149 beats per minute. Cardiovascular exam revealed an irregularly irregular rhythm, and pulmonary exam revealed mild expiratory wheezing. Abdomen was tender. Electrocardiogram revealed atrial fibrillation with rapid ventricular response which responded to intravenous diltiazem. Labs revealed TSH of < 0.1 mU/L and free T4 of 2.82 ng/dL, a positive TSH-receptor and thyroid peroxidase antibodies suggesting Grave’s thyrotoxicosis. A transthoracic echocardiogram reported an ejection fraction of 55-60%, with mild to moderate mitral regurgitation (MR) and moderate to severe tricuspid regurgitation (TR) and dilated right heart chambers. Pulmonary artery systolic pressure was 52 mm Hg. Transesophageal echocardiogram revealed a myxomatous tricuspid valve with thickening and malcoaptation of the leaflets and moderate to severe TR, mild to moderate MR with mild thickening of the mitral valve leaflets. Abdominal ultrasound revealed wall thickening of the gall bladder concerning for acute cholecystitis. She underwent laparoscopic cholecystectomy and was discharged in stable condition on methimazole for her thyroid disease, and on oral diltiazem for rate control and anticoagulation for atrial fibrillation. Follow-up visit with her cardiologist few months later documented absence of cardiac symptoms, and no murmurs were reported on physical examination. This case underscores the importance of maintaining a high index of suspicion for hyperthyroidism when faced with significant newly diagnosed pulmonary hypertension and TR, as treatment of the thyroid abnormalities can reverse these cardiac findings.

Triad of exophthalmos, pretibial myxedema, and acropachy in a patient with Graves' disease

Graves' disease is an autoimmune disorder of the thyroid gland with characteristic peripheral manifestations. The most common clinical findings include ophthalmopathy in 30% of patients, dermopathy (pretibial myxedema) in 4% of patients, and thyroid acropachy in 1% of patients. The triad of exophthalmos, pretibial myxedema, and acropachy occurs in less than 1% of patients. We present a case of Graves' disease with the clinical triad of eye disease, dermopathy, and acropachy.

Pretibial myxedema as the initial manifestation of Graves' disease

Pretibial myxedema (PM) is a localized thickening of the pretibial skin due to accumulation of acid mucopolysacharides (glycosaminoglycans). Its pathogenesis is still under investigation. Pretibial myxedema, exophthalmus and thyroid acropachy are the dassic extrathyroidal manifestations of Graves' disease. Almost invariably, PM follows the onset of ophthalmopathy, developing after the diagnosis and treatment of hyperthyroidism. Pretibial myxedema preceding Graves' ophthalmopathy is rare. We report the case of a 28-year-old Greek woman, who presented with multiple, asymptomatic nodules and plaques of the lower legs in the absence of other physical findings. Histopathologic examination revealed deposition of mucopolysacharides in the lower dermis. Laboratory investigation showed elevated serum T3 and T4 and depressed TSH levels. In our patient, pretibial myxedema was the earliest manifestation, leading to the diagnosis of Graves' disease.

Animal models of thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is an autoimmune condition most frequently associated with Graves' disease (GD). The thyrotropin receptor (TSHR) is an important target of the autoimmune response in both disorders. The last 5 years have seen some progress in the development of animal models, induced with TSHR preparations and reproducing some or all of the features of GD and TAO with variable incidence. The most promising approaches have used: (1) treatment of AKR/N mice with cells transfected with the homologous major histocompatibility complex class II molecule to the recipients and the full-length human or murine TSHR. Approximately 20% of mice develop thyroid-stimulating antibodies (TSAB) and increased thyroxine levels but no thyroiditis; (2) transfer of TSHR primed T cells to naive syngeneic recipients. Approximately 65% of BALBc mice develop thyroiditis and orbital changes similar to TAO; (3) genetic immunization of NMRI outbred mice with the full-length human TSHR. Approximately 20% of mice develop TSAB, hyperthyroidism, and orbital changes.

Igs from patients with Graves' disease induce the expression of T cell chemoattractants in their fibroblasts

Thyroid-associated ophthalmopathy and dermopathy are connective tissue manifestations of Graves' disease (GD). Tissue remodeling is a prominent feature of both and is apparently driven by recruited T cells. In this study, we report that IgG isolated from patients with GD (GD-IgG) up-regulates T lymphocyte chemoattractant activity in GD-derived fibroblasts from orbit, thyroid, and several regions of skin. This chemoattractant activity, absent in fibroblasts from donors without known thyroid disease, is partially susceptible to neutralization by anti-IL-16 and anti-RANTES Abs. IL-16 is a CD4(+)-specific chemoattractant and RANTES is a C-C-type chemokine. IL-16 and RANTES protein levels, as determined by specific ELISAs, are substantially increased by GD-IgG in GD fibroblasts. Addition of the macrolide, rapamycin, to fibroblast culture medium blocked the up-regulation by GD-IgG of IL-16, implicating the FRAP/mTOR/p70(s6k) pathway in the induction of IL-16 expression. These findings suggest a specific mechanism for activation of fibroblasts in GD resulting in the recruitment of T cells. They may provide insight into a missing link between the glandular and extrathyroidal manifestations of GD.

Elephantiasic pretibial myxedema: insight into and a hypothesis regarding the pathogenesis of the extrathyroidal manifestations of Graves' disease

The basis for the extrathyroidal manifestations of Graves' ophthalmopathy (GO) and dermopathy are not well understood. We describe immunohistochemical studies on the skin of a patient with an extreme, elephantiasic form of Graves' dermopathy that developed after periods of prolonged standing with dependent edema. Excision of part of the lesion with subsequent skin grafting from a normal donor site resulted in recurrence of the disease at the original site as well as in development of disease at the donor site. A murine monoclonal antibody reacted with the thyrotropin receptor (TSHR) or a cross-reacting protein in fibroblast-like cells in the patient's upper dermis and, surprisingly, with dermal cells from unaffected individuals. The patient's dermis containing lymphoid follicles comprising B cells and CD3+, CD4+ T cells, with few CD8+ T cells. CD21+ cells (most likely follicular dendritic cells) were also present in the dermis. Based on past and present observations, we raise an unifying hypothesis to explain the diverse extrathyroidal manifestations of Graves' disease and their apparent lack of association with TSHR autoantibodies. As opposed to the present concept that these phenomena relate to site-specific properties on preadipocytes or fibroblasts, we suggest that clinically evidence GO and dermopathy are primarily caused by local factors (particularly in the orbit) superimposed on a systemic, low-grade connective tissue inflammation.

Treatment of Graves' disease: the advantages of surgery

The authors and others believe that surgery (thyroidectomy) is underused in the treatment for patients with Graves' disease. It is the most rapid and consistent method of making the patient euthyroid; it avoids the possible long-term risks of radioactive iodine; and it provides tissue for histologic examination. Children, young women, pregnant women, and patients with coexistent thyroid nodules are ideal candidates for thyroidectomy. It also is the treatment of choice for patients with Graves' ophthalmopathy. Patients should be rendered euthyroid before thyroidectomy. Although the operation is technically more difficult than operating on patients with nontoxic goiter or thyroid neoplasms because of the vascularity of the thyroid gland, this difference is small, and the complication rates are low. The authors recommend the Hartley-Dunhill operation (total thyroidectomy on one side and subtotal thyroidectomy on the other side, leaving about 4 to 5 g of thyroid tissue) for most patients and total thyroidectomy for patients with Graves' ophthalmopathy. In patients with recurrent or persistent thyroid cancer who fail to respond to surgery and radioactive iodine ablation, immunosuppressive therapy should be considered.

Graves' dermopathy: does octreotide scintigraphy predict the response to octreotide treatment?

We report on three patients with severe Graves' dermopathy who were treated with octreotide despite a negative octreotide scintigraphy. One patient showed a complete recovery while two others had a partial response. In contrast to active Graves' ophthalmopathy, an octreotide scintigraphy appears not to be useful for pretreatment identification of patients with Graves' dermopathy who are likely to respond to octreotide treatment.