Prevalence and Clinical Characteristics of Pretibial Myxedema in Chinese Outpatients With Thyroid Diseases

Liao

et al. 2020

J Clin Med Res

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Background: Pretibial myxedema (PTM) is a local mucinous dermopathy associated with thyroid diseases. Since the etiology of PTM is unclear, the aim of this study is to identify the risk factors for PTM and their etiological roles in PTM occurrence. Methods: A large-scale case-control study (n = 1,200) was performed to identify risk factors for PTM by calculating odds ratio (OR) values and 95% confidential intervals. The PTM group entered a glucocorticoid treatment trial. Patients with complete response were followed up to the first relapse in a cohort study. The relative risk (RR) values of the main risk factors were calculated for PTM relapse to test their etiological roles. Results: Among the 19 factors, six risk factors were identified: thyroid-stimulating hormone (TSH) receptor antibody (TRAb) (OR 42.93), autoimmune thyroid disease (AITD) or AITD history (OR 10.30), local trauma (OR 6.55), venous stasis posture (OR 6.16), cigarette smoking (OR 4.48), and age (OR 1.05). Serum TRAb levels were positively correlated with the severity of PTM. Of note, 371/400 patients received glucocorticoid treatment, and 330 achieved complete response. The serum TRAb levels after treatment decreased dramatically compared with those before treatment. After stopping glucocorticoid treatment, serum TRAb levels increased significantly when PTM relapsed (P < 0.001). In 165 relapse cases, an increase in serum TRAb levels occurred first, followed by persistent venous stasis posture or local trauma and finally PTM. The RR of elevated serum TRAb levels was 6.73 in PTM relapse cases. In the elevated serum TRAb level group, the RRs of local trauma, venous stasis posture, and local trauma plus venous stasis posture were 8.81, 6.5, and 8.84, respectively, for PTM relapse cases. Conclusions: TSHR autoimmunity and local factors in the six identified risk factors are the main causes of PTM occurrence.

Section: Introductionmentioning

confidence: 99%

Thyroid-Stimulating Hormone Receptor Autoimmunity and Local Factors in Multiple Risk Factors Are Mainly Involved in the Occurrence of Pretibial Myxedema

Liao

et al. 2020

J Clin Med Res

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“…PTM occurs in 1.6% of patients with thyroid diseases, 1.7% of patients with Grave's thyrotoxicosis [ 5 ], and 15% of patients with severe Graves' ophthalmopathy [ 21 ]. 97% of patients with PTM are associated with Graves' ophthalmopathy [ 21 ] and 20% associated with acropachy [ 4 ].…”

Section: Discussionmentioning

confidence: 99%

“…Isolated cases in PubMed database reported nodule, plaque, tumor, and elephantiasic variants [ 24 – 27 ]. Some large case series reported more variants [ 5 , 17 , 21 , 28 , 29 ]. In the largest case series, the morphology of PTM consisted of 6 variants and its subvariants.…”

Section: Discussionmentioning

confidence: 99%

“…While it is commonly located on the pretibial area, actually, it could occur on the skin of all body sites. It is relatively rare in clinical practice because its prevalence in Grave's disease is only 1.5–1.7% [ 4 , 5 ]. Up to now, it has been widely accepted that most cases of PTM are inconspicuous and tend to resolve spontaneously [ 6 – 11 ].…”

Section: Introductionmentioning

confidence: 99%

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

Journal of Thyroid Research

Wang

Zeng

et al. 2016

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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.

“…Localized myxedema or thyroid dermopathy is an uncommon dermopathy associated with autoimmune thyroid diseases [ 1 ], first reported by Hektoen in 1895 [ 2 ]. Its prevalence is 1.6% in thyroid diseases in China [ 3 ]. Commonly located at the pretibial area, it is also often known as pretibial myxedema (PTM).…”

Section: Introductionmentioning

confidence: 99%

A Randomized Controlled Trial of Intralesional Glucocorticoid for Treating Pretibial Myxedema

Chen

et al. 2015

J Clin Med Res

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BackgroundPretibial myxedema (PTM) is an uncommon dermopathy associated with autoimmune thyroid diseases. Now it is thought to be autoimmune and its treatment with glucocorticoid is helpful. However, it has not been evaluated.MethodsA prospective randomized controlled trial was performed in 110 patients with PTM to evaluate the efficacy and safety of triamcinolone acetonide with intralesional injection once every 3 days and once every 7 days. Randomization was performed with drawing lots and it was also stratified according to variants of PTM lesions. In the follow-up, recurrent rates were observed. The SPSS Statistics 17.0 Software was used in the statistical analysis.ResultsThe complete response rates were 78.2%, 83.6%, and 87.3% in regimen 1 and 50.9%, 89.1%, and 90.9% in regimen 2 at 3 weeks, 7 weeks and the end of therapy, respectively. Regimen 1 had an earlier efficacy than regimen 2, but at 7 weeks and end of therapy, there were no differences between two regimens. The majority of non-severe variants got complete response but severe variants did not. The adverse reaction rates in regimen 1 were higher and earlier than those in regimen 2. Adverse reaction occurring time in regimen 1 was shorter than that in regimen 2. Recurrent rates were 31.25% and 32% in regimens 1 and 2 at 3.5-year follow-up.ConclusionsFor its autoimmune, hyperplasia and disabled features, early treatment of PTM with glucocorticoid is necessary to get complete response. Dosage and frequency of intralesional steroid injection and lesional variants influence the efficacy of PTM. Once every 7 days is a better regimen.