Euthyroid pretibial myxedema

Pretibial myxedema in a euthyroid patient: a case report

Background

Pretibial myxedema also known as localized myxedema, thyroid dermopathy, or infiltrative dermopathy and rarely as localized mucinosis is an infrequent manifestation of Graves’ disease. It can appear before, during, or after the thyrotoxic state. Euthyroid pretibial myxedema is a rare presentation with few case reports in the literature. This case highlights the importance of considering pretibial myxedema when characteristic skin lesions are observed in a euthyroid patient.

Case presentation

A 72-year old male Ethiopian patient with a very rare presentation of biopsy-proven pretibial myxedema in a euthyroid state without history of thyroid disease and absence of thyroid autoimmune markers. Resolution of skin lesion was achieved after topical corticosteroid application.

Conclusion

Absence of history of thyroid disorder and normal thyroid function tests should not exclude the diagnosis of pretibial myxedema.

Pretibial myxedema in a euthyroid patient

Pretibial myxedema (PM) is a rare extrathyroidal manifestation of Graves' disease (GD), usually during the hyperthyroid state, coexisting with orbitopathy. We describe a rare case of a biopsy-proven PM in a euthyroid patient, without history of GD or Hashimoto's thyroiditis. Assessment of commonly reported thyroid autoantibodies, such as thyroid peroxidase and thyroglobulin autoantibodies, thyroid stimulating immunoglobulins and thyroid binding inhibitory immunoglobulins, was negative. Resolution of skin pathology was achieved after topical application of corticosteroids and was sustained 1 year later.

Pretibial mucinosis in an euthyroid patient

A case of exuberant pretibial mucinosis in a patient with normal thyroid function is reported. A review of literature on possible etiologies other than thyroid disease for the accumulation of mucin in the pretibial area is presented. In the patient described, it is possible that vascular insufficiency is involved. However, this is not the only factor responsible for the accumulation of mucin, since there are still unidentified causes and many patients with vascular diseases do not develop similar injuries.

Chronic obesity lymphoedematous mucinosis: three cases of pretibial mucinosis in obese patients with pitting oedema

Pretibial mucin deposition on the shins is known as pretibial myxoedema. We report three patients with pretibial mucinosis without thyroid disease. The patients were characterized clinically by morbid obesity and bilateral lower extremity pitting oedema with gradual and painless onset, and that did not involve the feet and ankles. Vesicles, semitranslucent papules or a woody plaque were found on the shins. Histologically, patients showed characteristic features of epidermal atrophy with effacement of the rete ridge pattern, separation of collagen bundles associated with oedema with stellate to linear fibroblasts, upward-running increased capillary and small vessels with haemosiderin deposition, and mucin deposition at the superficial papillary dermis and around the vessels. We propose that the present cases of 'chronic obesity lymphoedematous mucinosis' belong to the clinical entity of pretibial mucinosis.

Euthyroid pretibial myxedema

OBJECTIVE

To describe a case of biopsy-proven pretibial myxedema in a man with normal thyroid function.

METHODS

We present the pertinent clinical and laboratory data for the current case and review previously published information on pretibial myxedema.

RESULTS

Our patient, a 53-year-old man, had the characteristic lesions of pretibial myxedema on the anterolateral aspects of his calves. Laboratory tests showed normal thyroid function. The thyroid-stimulating immunoglobulin value was above normal. No exophthalmos or goiter was present. This uncommon dermopathy is typically associated with Graves' disease, accompanied by clinical hyperthyroidism, ophthalmopathy, and goiter.

CONCLUSION

The pathogenesis of pretibial myxedema remains elusive. It is presumed to be an autoimmune phenomenon attributable to the presence of serum thyroid-stimulating immunoglobulin, although immunofluorescence studies have failed to demonstrate a direct role for such an immunoglobulin. Only two other cases of biopsy-proven pretibial myxedema in a euthyroid patient were found in the literature.

Chronic autoimmune thyroiditis and rheumatic manifestations

A variety of rheumatic manifestations have been described in association with autoimmune thyroiditis. In the past, most of these manifestations were attributed to the underlying thyroid dysfunction, in particular hypothyroidism. However, a responsibility of the mechanisms involved in the autoimmunity rather than a direct action of thyroid hormones seems supported by the evidences that some rheumatic manifestations may occur even in euthyroid patients, or that they are more frequent in hypothyroid patient with autoimmune thyroiditis than in those without this disease. Rheumatic manifestations could be sometimes attributable to the autoimmune rheumatic diseases frequently associated with autoimmune thyroiditis, such as Sjögren's syndrome, rheumatoid arthritis, systemic lupus erythematosus, or scleroderma. Among the most important or frequent rheumatic manifestations there are a mild non-erosive variety of arthritis, polyarthralgia, myalgia, and sicca syndrome without a true Sjögren's syndrome. Although the possible pathogenesis of these manifestations is not completely established, some hypotheses may be proposed, including a role of autoantibodies characteristics of autoimmune thyroiditis, a possible overlap between autoimmune thyroiditis and some autoimmune rheumatic diseases, and a systemic inflammatory reaction associated with thyroiditis.

Pretibial myxoedema associated with Hashimoto's thyroiditis

Pretibial myxoedema is a cutaneous mucinosis typically associated with Graves' disease, although it may also develop in subjects with non-thyrotoxic thyroid pathologies. This report presents a rare case of pretibial myxoedema occurring in a 58-year-old woman with biopsy-proven Hashimoto's thyroiditis. The hypothetical pathogenetic link between the two disorders is discussed with particular attention to the role of thyroid stimulating hormone receptor antibodies.

Elephantiasic pretibial myxedema: a novel treatment for an uncommon disorder

Pretibial myxedema is a known manifestation of Graves' disease. Much less common is the elephantiasis nostras variant, which is often refractory to treatment. We therefore elected to try a new therapy, often used for the management of chronic lymphedema, called complete decongestive physiotherapy. After 6 weeks of intensive treatment, our patient lost 37 pounds and had reduced her edema volume by 47%. Her skin softened with decreased lymph seepage and she became mobile for the first time in years. At a 2-year follow-up visit, she exhibited sustained improvement. This case demonstrates that complete decongestive physiotherapy can provide effective, long-term control of this disease process. We suggest that complete decongestive physiotherapy be considered in patients with severe forms of pretibial myxedema, as well as those with refractory lymphedema.

Pretibial myxoedema presenting as a scar infiltrate

A 41-year-old man developed pretibial myxoedema localized to scars following treatment for hyperthyroidism. Pre-existing scars on both lower legs, present for more than 20 years, were infiltrated with firm and nonpitting nodules and plaques over his shins. The clinical presentation of this patient highlights pretibial myxoedema as a cause of scar infiltration. The pathogenesis of pretibial myxoedema is reviewed.