Recurrent Episodes of Thyrotoxicosis in a Man following Pregnancies of his Spouse with Hashimoto's Thyroiditis

Over an 8-year period, a male patient presented three times to an endocrinologist with strikingly similar presentations, including palpitations, anxiety, and tremors. Each of his presentations occurred following either the birth of one of his two children or his wife's late termination of pregnancy. This patient's illness followed the typical time course of silent thyroiditis: hyperthyroidism, followed by euthyroidism, a late hypothyroid phase, and then a complete resolution of symptoms and normalization of thyroid function tests over a period of several months. We discuss the curious clinical presentation, diagnostic evaluation, and a literature review of alternate explanations for this patient's condition, including a discussion of the impact of seasonal shift, spousal's autoimmune disease, stress, and evolutionary changes in males postpartum. Although the differential diagnosis is broad in this case and the thyrotoxicosis could have coincidentally followed pregnancies of the patient's wife, documented hormonal changes in men during postpartum period in conjunction with the timeline of the patient's condition are suggestive of recurrent “sympathetic” postpartum thyroiditis. To our knowledge, this is the first case report of recurrent painless thyroiditis in a man following pregnancies of his wife with Hashimoto's thyroiditis.


Introduction
Silent thyroiditis, also known as painless or subacute lymphocytic thyroiditis, is one of several autoimmune thyroid disorders [1]. The clinical presentation of postpartum thyroiditis is virtually identical to that of silent thyroiditis, except that postpartum thyroiditis occurs in women within 1 year after delivery and rarely develops one month postpartum. It is typically associated with the development of either transient hyperthyroidism or hypothyroidism or both up to 1 year postpartum with eventual return to a euthyroid state [2,3]. Usually, patients have a brief phase of thyrotoxicosis lasting 2-4 weeks, followed by hypothyroidism for 4-12 weeks and then resolution and a return to euthyroidism [4]. In the United States, postpartum thyroiditis occurs in approximately 5-10% of women. The incidence can be greater in certain high-risk populations, including those with a history of autoimmune disorders, with previous thyroid dysfunction including previous postpartum thyroiditis (70% chance of recurrence with subsequent pregnancies), and/or having a family history of thyroid dysfunction [5,6]. We present a curious case of a man who developed painless thyroiditis three times coinciding with the postpartum period of his wife with Hashimoto's thyroiditis.

Case Report
A 33-year-old male, with a past medical history of hyperlipidemia, seasonal allergies, and occasional sleep problems, originally presented feeling anxious, hot, and jittery, with recent weight loss and increased frequency of his bowel movements. He appeared slightly anxious, but the rest of exam was unremarkable, including thyroid examination which did not reveal any enlargement, tenderness, 2 Case Reports in Endocrinology  Table 1 summarizes these findings. Of note, the patient's wife did not experience any similar symptoms during or following the three pregnancies. She has a history of Hashimoto's thyroiditis, diagnosed in 2011, when she initially presented with TSH of 96 IU/Ml, and is maintained on levothyroxine with dose adjustments during gestation.

Discussion
The case presented here describes recurrent episodes of thyrotoxicosis in a man following pregnancies of his spouse who has treated Hashimoto's thyroiditis. The differential diagnosis for his presentation is broad, and multiple factors might have contributed to this patient's condition. For instance, the thyroid supplementation of the patient's wife suggests that surreptitious ingestion of thyroid hormones is possible. However, the cyclical course of this patient's disease is not consistent with exogenous thyroid hormone use. Given that the recurrent abnormal TFT levels occurred in the summer months, seasonal variations in thyroid levels must be considered, though these are unlikely to be solely responsible for the thyroid hormone variations. The time course of the disease is on the other hand consistent with silent thyroiditis. Patient transitioned from a state of hyperthyroidism to a state of mild hypothyroidism, followed by a resolution of thyroid function tests over a 3-4-month period. Documented hormonal changes in men, during postpartum period, whether stress related or evolutionary in nature, are suggestive of the diagnosis of "sympathetic" postpartum thyroiditis.
Research shows that the environmental impact of living with a spouse suffering from an autoimmune disease should not be ignored. Hemminki et al. looked at epidemiology of Grave's disease and the evidence of familial risks between family members. The study found a high disease concordance of 2.75 between spouses in Swedish population over the course of 20 years, which suggests the operation of some form of environmental sharing. The study mentions similar correlation between spouses and rheumatoid arthritis and amyotrophic lateral sclerosis. Shared smoking habits, psychosocial risk factors, stress, and infections are believed to be the mechanism behind the spouse correlation, all of which may precipitate many autoimmune conditions [7]. Emilsson et al. argued that first-degree relatives and spouses of individuals with celiac disease are at increased risk of nonceliac autoimmune disease. He also suggested that possible sharing of microbiome and the environment with their spouse might impact the risk of developing and diagnosing other autoimmune diseases [8].
Cyclical thyroid hormone changes found in this patient could have been caused by seasonal shifts. In a study about physiological variations in thyroid hormones Fisher states that the levels of T4 are statistically higher in winter as opposed to summer, although the variation is minimal. He attributes this variation to an effect of cold, which accelerates the peripheral metabolism of thyroid hormone during the winter months [9]. A study by Smals et al. found a seasonal variation in circulating serum T4 and T3 levels, inversely correlating with the seasonally altering environmental temperature. Lowest serum T4 and T3 levels were found in the summer [10].
Given that the cycles of thyroid hormone shifts in this patient coincided with his wife's pregnancies, it is important to consider the likelihood of men experiencing similar hormonal changes to women during the postpartum period. In a study by Storey et al. hormone concentrations and responses to infant stimuli in expectant and new fathers living with their partners were measured in order to determine whether men can experience changes that parallel the dramatic shifts seen in pregnant women. The result was that men and women had similar stage-specific differences in hormone levels, including higher concentrations of prolactin and cortisol in the period just before the births and lower postnatal concentrations of testosterone and estradiol. Men reporting pregnancy symptoms and men reporting strong emotional responses to the stimuli had significantly higher prolactin concentrations and experienced a larger testosterone decrease between the two blood samples than men without these responses. The pattern of hormonal change in men demonstrated in this study and its absence in nonpaternal species suggests that hormones may play a role in priming males to provide care for their offspring. From an evolutionary standpoint, it appears that the testosterone decrease in the postnatal period may reduce male's tendencies to engage in nonnurturing behaviors and thus promote greater paternal responsiveness [11].
Considering the similarities in the presentation of autoimmune thyroid diseases, one must often rely on the most common manifestation to determine the diagnosis. For a patient suffering from silent thyroiditis, a presence of ophthalmopathy and/or a thyroid bruit during the thyrotoxic stage would be a strong indication of Grave's disease. Neither presentation was found in this patient. Grave's disease was definitively ruled out by a markedly decreased thyroid uptake on a nuclear medicine scan. Most patients with silent thyroiditis have normal thyroid function at one year. In patients suffering from postpartum thyroiditis, 30 to 50% of patients develop permanent hypothyroidism within nine years [12,13]. Such appears to be the case with this patient as his TSH levels were found to be elevated during the last two visits. Though the timing of this patient's symptoms is strongly suggestive of postpartum thyroiditis, a causal relationship between episodes of recurrent painless thyroiditis (silent thyroiditis) and spousal postpartum periods has not yet been established.

Conclusion
The case presented here poses a question whether hormonal changes seen during a postpartum period in a female can manifest themselves in the male spouse. To our knowledge, this is the first case report of a recurrent and possibly "sympathetic" postpartum thyroiditis in a male. Although differential diagnosis is broad, a plausible link between the postpartum period and the coinciding thyrotoxicosis in the male spouse has been presented. A number of documented cases showed that levels of several hormones in men change significantly during their spouse's postpartum period. Such changes, as described, may actually serve an evolutionary purpose. An alternative explanation for our patient's symptoms was established by the inclusion of studies showing a link between living with a spouse suffering from an autoimmune disease and the likelihood of the male partner developing a similar condition. Though more research is required to establish causality, postpartum thyroiditis should be considered as a possible diagnosis for a male patient presenting with anxiety, palpitations, weight loss, and tremors coinciding with postpartum period of his partner.