Elephantiasic pretibial myxedema in a patient with graves disease that resolved after 131I treatment

Pretibial Myxedema Presenting as Severe Elephantiasis

Elephantiasis is a symptom characterized by the thickening of the skin and underlying tissues in the legs. Pretibial myxedema (PTM) is a non-frequent manifestation of autoimmune thyroiditis, particularly Graves' disease. Lesions of myxedema occur most commonly on the pretibial surfaces, also develop at sites of previous injury or scars and other areas. A 49-year-old male presented with severe elephantiasis on the both pretibial areas, dorsum of the feet, ankles and toes. Twenty years previously, he had received radioactive iodine treatment for thyrotoxicosis. Laboratory tests showed that the patient's thyroid function was normal, but the level of thyroid stimulating hormone (TSH) receptor antibodies was very high (>40 IU/L). The biopsy confirmed PTM. Interestingly, the connective tissue was stained with the TSH receptor antibodies in the deep dermis. Elephantiasic PTM is a severe form of the myxedema and there is few reported case. We report a rare case of PTM with appearance of severe elephantiasis.

Treatment of pretibial myxedema with intralesional immunomodulating therapy

Objective

Local immune regulation therapy has been one of the therapeutic methods used for the treatment of autoimmune thyroid disease in patients with pretibial myxedema (PTM). However, the poor response rate and high recurrence rate are still major problems. Whether a premixed corticosteroid, compound betamethasone, could enhance remission rate and decrease recurrence rate in patients with PTM was investigated in the present study.

Subjects and methods

We have performed a clinical utility observation of compound betamethasone with intralesional injections based on basic thyroid disease treatment in 32 PTM patients between January 2008 and August 2016. The patients were followed up for 2 years, and the clinical outcomes and side effects were calculated and analyzed.

Results

All patients had a complete remission after different times of injection. A total of 21.7% patients had complete remission with one time of injection, 34.8% with two times of injection, 17.4% with three times of injection, 4.3% with four times of injection, and 4.3% with five times of injection. In all, 56.3% patients with a disease duration of <6 months had complete remission after a 1-month treatment, 37.5% patients with a disease duration between 6 months and 12 months had complete remission after a 2-month treatment, 3.1% patients with a disease duration of 2 years had complete remission after a 5-month treatment, and 3.1% with a disease duration of 5 years had complete remission after a 7-month treatment.

Conclusion

Compound betamethasone with multipoint intralesional injection is a feasible, effective, and secure novel strategy in the treatment of PTM.

Morphological Diversity of Pretibial Myxedema and Its Mechanism of Evolving Process and Outcome: A Retrospective Study of 216 Cases

Background. Pretibial myxedema (PTM) is a rare dermopathy. The morphologic features and mechanism of its evolving process are not reported in large case series. Methods. 216 cases with PTM were retrospectively reviewed to analyze demographics, history, lesional morphology and its evolving process, histopathology and immunohistochemistry, serum TRAb levels, treatment, and outcome. Results. First appearing lesions evolved into 6 variants that were correlated with serum TRAb levels. Subvariants were caused by different kinds and frequencies of local trauma. The evolving process could be classified into 4 stages that were correlated with serum TRAb levels and perivascular infiltration of CD8+ and CD4+ lymphocytes. Serum TRAb levels at remission and in nonrecurred cases became lower than those before therapy and in recurred cases, respectively, but increased when PTM relapsed. TRAb level in nodule variant went down invariably with the extension of course and its autoimmune activity had a trend to stop but in other 5 variants TRAb levels fluctuated. Their autoimmune activities had no trends to stop and clinically worsen through intermittent repeats of active and stable stages. Conclusions. In the chronic course of PTM, nodule variant is self-limited and other 5 variants are not self-limited. PTM needed early treatment to avoid severe variants.