methimazole and Myxedema

We report a case of pretibial myxedema with Graves' disease in an 18-year-old Japanese woman. The physical examination revealed waxy indurated plaques with prominent hair follicle openings and nonpitting edema disseminated on her lower legs. Histology from an edematous lesion revealed that the dermis was markedly thickened with abundant mucin, especially hyaluronic acid, and the collagen fibers in this portion were splitting up into fibrils. We also reviewed 112 cases of pretibial myxedema reported in the Japanese literature.

Topics: Adolescent; Antithyroid Agents; Biopsy, Needle; Female; Graves Disease; Humans; Japan; Leg Dermatoses; Methimazole; Myxedema

Topics: Administration, Cutaneous; Adult; Betamethasone; Biopsy; Drug Therapy, Combination; Humans; Hyperthyroidism; Leg Dermatoses; Male; Methimazole; Myxedema; Occlusive Dressings; Propranolol; Skin; Treatment Outcome

Localized myxoedema is a rare dermopathy in patients with Graves' disease. The pretibial area is the most commonly affected region but herein we present a case of myxoedema of the big toe.. A 44-year-old male with Graves' disease ongoing for seven years presented bilateral ophthalmopathy and myxoedema of the big toes. The myxoedema was treated successfully with intralesional steroids.. The physiopathology of myxoedema involves fibroblast activation and glycosaminoglycan production. This activation could result from stimulation of TSH receptors at their surface by TSH receptor antibodies (TRAK) or from an inflammatory process. The pretibial topography may be related to the high frequency in this area of microtrauma, with modulation of the cytokine microenvironment.. The atypical localization seems to correlate with a Koebner phenomenon. Treatment of Graves' disease is generally insufficient to resolve the cutaneous problems. Topical corticosteroid therapy generally results in rapid improvement of recent lesions.

Topics: Adult; Biopsy; Carbimazole; Decompression, Surgical; Fibroblasts; Foot Dermatoses; Glycosaminoglycans; Graves Disease; Graves Ophthalmopathy; Hormone Replacement Therapy; Humans; Immunoglobulins, Thyroid-Stimulating; Immunosuppressive Agents; Injections, Intralesional; Male; Methimazole; Myxedema; Receptors, Thyrotropin; Thyroidectomy; Thyroxine; Toes; Triamcinolone

Thyroid destruction leading to endemic myxoedematous cretinism is highly prevalent in central Africa, where iodine (I) and selenium (SE) deficiencies as well as thiocyanate (SCN) overload are combined. All three factors have been studied experimentally in the etiology of the disease, but they have never been studied in combination. In a model using rats, we have previously shown that combining I and SE deficiencies increases the sensitivity of the thyroid to necrosis after iodide overload, an event unlikely to occur in the African situation. To develop a model that would more closely fit with the epidemiological findings, we have determined whether an SCN overload would also result in thyroid necrosis as does the I overload. The combination of the three factors increased by 3.5 times the amount of necrotic cells, from 5.5 +/- 0.3% in the I-SE+ thyroids to 18.9 +/- 1.6% in the I-SE-SCN-overloaded ones. Methimazole administration prevented the SCN-induced necrosis. SE- thyroids evolved to fibrosis, whereas SE+ thyroids did not. TGFbeta was prominent in macrophages present in SE- glands. Thyroid destruction in central Africa might therefore originate from the interaction of three factors: I and SE deficiencies by increasing H(2)O(2) accumulation, SE deficiency by decreasing cell defense and promoting fibrosis, and SCN overload by triggering follicular cell necrosis.

Topics: Africa, Central; Animals; Antithyroid Agents; Congenital Hypothyroidism; Disease Models, Animal; Endemic Diseases; Female; Fibrosis; Hydrogen Peroxide; Inflammation; Iodine; Macrophages; Methimazole; Myxedema; Necrosis; Perchlorates; Rats; Rats, Wistar; Selenium; Sodium Compounds; Thiocyanates; Thyroid Gland; Transforming Growth Factor beta

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.

Topics: Administration, Oral; Administration, Topical; Adrenal Cortex Hormones; Adult; Biopsy, Needle; Diagnosis, Differential; Female; Follow-Up Studies; Graves Disease; Humans; Immunohistochemistry; Lower Extremity; Methimazole; Myxedema; Severity of Illness Index; Thyroid Function Tests; Treatment Outcome

Each of the endocrine emergencies discussed here--adrenal crisis, myxedema coma, and thyroid storm--represents decompensation of a long-standing endocrine disorder and is precipitated in most cases by some stressful event. Each necessitates immediate, aggressive therapy. Even with such therapy, the mortality rate remains 30% to 50% for myxedema coma and 30% to 40% for thyroid storm. Therapy must be instituted on the basis of strong clinical suspicion, without delay for results of specific hormone assays to confirm the diagnosis. Although some risks may be inherent in this approach, they are minimal compared with the risks of delaying therapy until laboratory confirmation can be obtained. Immediate therapy consists of specific measures to correct the hormone deficit or excess; the precipitating cause should then be sought and treated.

Topics: Addison Disease; Coma; Emergencies; Humans; Hydrocortisone; Methimazole; Myxedema; Stress, Psychological; Thyroid Crisis; Thyroid Hormones

Topics: Animals; Basement Membrane; Capillaries; Disease Models, Animal; Dogs; Inclusion Bodies; Lipid Metabolism; Male; Methimazole; Microscopy, Electron; Mitochondria, Muscle; Myocardium; Myxedema; Pectoralis Muscles; Propylthiouracil

Topics: Adult; Antibody Formation; Antithyroid Agents; Autoantibodies; Exophthalmos; Female; Graves Disease; Hemagglutination Tests; Humans; Imidazoles; Immunosuppressive Agents; Iodine Isotopes; Long-Acting Thyroid Stimulator; Male; Methimazole; Middle Aged; Myxedema; Thyroglobulin

Topics: Adult; Aged; Antibodies; Chronic Disease; Female; Humans; Hyperthyroidism; Hypothyroidism; Iodine Isotopes; Male; Methimazole; Middle Aged; Myxedema; Propranolol; Propylthiouracil; Pulse; Thiocyanates; Thyroid Diseases; Thyroid Function Tests; Thyroiditis; Time Factors; Triiodothyronine

Topics: Adult; Aged; Blood Pressure; Cholesterol; Female; Humans; Hypertension; Hyperthyroidism; Hypothyroidism; Male; Methimazole; Middle Aged; Myxedema; Norepinephrine; Thyroid Hormones