The functioning of the skin depends on the general health of the body and is under the control of hormones especially thyroid. Hair growth, grease glands (sebaceous glands that produce grease or sebum) are affected by the thyroid. The actual thickness of the skin also depends on thyroid function. The skin manifestations of thyroid disease can present as non-specific signs secondary to thyroid imbalances such as hyperthyroidism (Graves’ disease) and hypothyroidism (Hashimoto’s thyroiditis), or can appear in association with other autoimmune diseases.
|Skin Changes in Hypothyroidism||Skin changes in Hyperthyroidism|
|Coarse, thin, scaly skin Swelling (hands, face, eyelids) Dry skin (xerosis) Dry, brittle, coarse hair Hair fall Pallor Loss of outer third of eyebrows Coarse, dull, thin, brittle nails Decreased sweating||Smooth, thin skin Thyroid dermopathy (Pre tibial myxedema) Warm skin Fine hair (“loses wave”) Hair fall Redness Hyperpigmentation, Blackening Shiny, soft, friable nails Increased sweating (hyperhydrosis)|
Pretibial myxedema (Thyroid dermopathy)
Patients with autoimmune mediated overactivity of thyroid may manifest a localized skin thickening identical to that seen in hypothyroidism. This was termed “pretibial myxedema” for many years due to its common identification in the leg area (the bone of leg is called as tibia), which is replaced by the newer term “thyroid dermopathy”.
Thyroid dermopathy almost always associated with eye disease. As such, dermopathy usually reflects a common cause of hyperthyroidism- Graves’ disease; in severe form. The commonest locations for thyroid dermopathy are the leg area and the distal lower extremities. There are reports of involvement of the upper extremities, shoulders, back, ears, nose and scar tissues. The lesions are raised and waxy with coloring ranging from light to yellowish brown. Lesions are aggravated by trauma and can recur if surgically removed.
Associated Autoimmune Phenomena
When thyroid disease is of autoimmune etiology, additional skin findings may be evident which reflect associated autoimmune disease. Autoimmune thyroid disease is sufficiently common that patients with other autoimmune disease deserve screening for thyroid dysfunction.
A list of autoimmune conditions apparent when examining the skin includes vitiligo, alopecia areata, pernicious anemia, bullous disorders (pemphigus, bullous pemphigoid, dermatitis herpetiformis), connective tissue diseases (lupus erythematosus, scleroderma), and urticaria.
This page is edited by Dr Tittu Oommen who is an expert Endocrinologist. Dr. Tittu is presently a Consultant Endocrinologist at PRS Hospital & Sree Gokulam Medical College, Thiruvananthapuram, Kerala.