Dermatologic disorders associated with thyroid disease

Editorial Perspective: Thyroid diseases need to be considered as contributing to the clinical picture in patients with a host of systemic and dermatologic disorders, many of which are classified as autoimmune. Imagine the following scenario: A 46-year-old woman with a known history of systemic lupus erythematosus complains of the recent development of leg weakness. The clinician needs to determine if this could be due to the lupus itself, a reaction to treatment (such as a steroid-induced myopathy), or if there is a concurrent pathologic process. Considering thyroid disease in this context should be routine; however, it is all too often forgotten as a diagnostic possibility. It is also essential to consider if a patient's medications may be affecting thyroid function. For example, if a patient with cutaneous T-cell lymphoma (CTCL) develops xerosis to the point of being considered as having an acquired ichthyosis, is the ichthyotic skin secondary to the lymphoma or to bexarotene-induced central hypothyroidism? This chapter emphasizes those disorders and medications that merit screening for thyroid disease in the appropriate clinical context, utilizing thyroid function studies or thyroid autoantibodies. The ability to treat thyroid disease should provide an impetus for assessing the thyroid status in patients with the maladies discussed in this chapter. Assessing thyroid function should be considered standard practice in patients with a personal or family history of any autoimmune disease.