The skin is the covering on our bodies - "our bag". The functioning of the skin depends on the general status of the body and it is controlled by hormones like the thyroid. Hair growth particularly depends on thyroid hormone. Grease glands (sebaceous glands that produce grease or sebum) also are affected by the thyroid. The actual thickness of the skin depends on thyroid function.
Hypothyroidism
In hypothyroidism there is a slow metabolic rate due to alteration of glandular function. This may be due to an autoimmune disease where for some reason the body destroys itself such as in HASHIMOTO'S THYROIDITIS or secondary failure due to tumour, infection or trauma. The slowed metabolic function results in insidious onset of tiredness, fatigue, leg cramps, etc. The skin is cold, dry and pale. The dryness can be extreme so that there is no sweating and the palms and soles get thick and dry.The skin colour can be yellow due to alteration in Vitamin A metabolism . Hair is lost all over - scalp, groin, even lateral eyebrows. Nails grow slowly and are brittle and thick.The most common skin change is a generalized myxedema or swelling due to a build up of ground substance in the foundation of the skin (dermis). The skin is swollen, dry, pale and waxy. One can slowly develop a broad nose, swollen lips and puffy eyelids. Wounds heal slowly.
Skin Changes in Hypothyroidism
Pale, cold, scaly, wrinkled skin Coarse, dry scalp and hair
Absence of sweating
Hair loss - scalp ,groin, lateral eyebrows, etc.
Skin colour - ivory - yellow Puffy edema (hands, face, eyelids)
Brittle nails
dry skin
Bruising Poor wound healing
Hyperthyroidism
Excessive thyroid hormone leads to an increase in basal metabolic rate—body functions go faster than normal.
Skin changes in hyperthyroidism
Intolerance of hot conditions – needing to wear less clothing than previously
Increased perspiration and warm, moist skin, which can lead to sweat rashes in skin folds
Increased hair shedding
Rapidly growing nails that may lift off the nail bed .
Thyroid disorders are sometimes associated with other diseases and skin changes.
Alopecia Areata- patchy hair loss
Pemphigus/Pemphigoid
Lupus erythematosus
Vitiligo is white patch disease.
Scleroderma
Treatment for dry skin:Avoid harsh irritating soaps and lotions.Use a cleansing bar just where one is dirty - hands, groin, axilla.Have a soak in the tub daily (not too hot).After soak use a moisturizer applied to the skin while the skin is moist to hold the moisture in. A simple formula is to mix Vaseline/Petrolatum 50-50 with an inexpensive cream. (Creams or lotions are usually too light to hold moisture in effectively on their own and Vaseline by itself is often too greasy).