Hyperthyroidism
Hyperthyroidism is an endocrine syndrome in which the thyroid gland is overactive, raising blood levels of the free thyroid hormones triiodothyronine (T3) and thyroxine (T4). The most common cause, accounting for 70–80% of cases, is Graves' disease (Basedow's disease), an autoimmune condition defined by autoantibodies that stimulate the TSH receptor (TRAb/TSI).
Thyroid hormone receptors (TR-alpha and TR-beta) are abundant on keratinocytes, fibroblasts, sweat glands and hair follicles, so excess T3 and T4 produces clear changes in the skin, nails and hair. Two skin signs are especially valuable diagnostic clues: pretibial myxedema (Graves' dermopathy) and Plummer's nails. At Haute-Derma, spotting these thyroid-related skin changes early helps steer endocrine testing, prevent thyroid storm and plan dermatologic and aesthetic treatment safely.
How Thyroid Hormone Affects Skin Cells and Connective Tissue
Excess thyroid hormone affects skin physiology broadly, through both direct biological effects and autoimmunity:
- Faster Metabolism and Impaired Heat Regulation:
- T3 and T4 boost Na+/K+-ATPase activity in skin cells, increasing oxygen consumption and whole-body heat production.
- The body responds by dilating the superficial skin capillaries (cutaneous vasodilation) and sweating more from the eccrine glands, so the skin is constantly warm, moist, smooth and flushed (palmar erythema/flushing).
- How Pretibial Myxedema Develops:
- In Graves' disease, TSH receptor antibodies (TRAb) do not only target the thyroid; they also bind TSH receptors (TSHR) on fibroblasts in the dermis of the shins.
- This activation drives the fibroblasts to produce and pile up glycosaminoglycans (GAGs), mainly hyaluronic acid and chondroitin sulfate. Because GAGs hold enormous amounts of water, the build-up forms firm, waterlogged, non-pitting plaques over the front of the shins.
- How Plummer's Nails Develop (Distal Onycholysis): Hyperthyroidism speeds up growth of the nail plate beyond the rate at which it can attach to the nail bed. This mismatch causes the plate to lift away from the bed, starting at the free edge and working inward (distal onycholysis), leaving a gap where bacteria or fungi can collect and causing the nail to curve upward.
- Diffuse Hair Shedding (Telogen Effluvium): High T3 and T4 shorten the life cycle of the hair follicle, abruptly switching hairs from the growth phase (anagen) to the resting phase (telogen) and causing diffuse thinning over the whole scalp.
Telling the Skin Signs of Hyperthyroidism From Hypothyroidism
| Feature | Hyperthyroidism (Graves') | Hypothyroidism (Hashimoto's) |
|---|---|---|
| Serum hormone levels | Very low TSH (< 0.01 mIU/L), high FT3 and FT4 | Very high TSH, low FT3 and FT4 |
| Skin texture and moisture | Warm, moist, soft skin that flushes easily; excessive sweating (hyperhidrosis) | Cold, dry, rough, scaly skin with a yellowish tint (carotenemia) |
| Type of swelling (edema) | Pretibial myxedema: well-defined, firm, non-pitting plaques on the shins | Generalized myxedema: non-pitting swelling of the face and around the eyes, with thick, waxy skin |
| Nail changes | Plummer's nails: distal onycholysis, upturned, soft nails | Dry, brittle nails that break easily, with longitudinal ridges and spoon-shaped nails (koilonychia) |
| Hair | Fine, soft hair with diffuse shedding (telogen effluvium) | Coarse, dry, brittle hair; loss of the outer third of the eyebrows (Queen Anne's sign) |
| Associated signs | Bulging eyes (exophthalmos), eyelid retraction, rapid heartbeat, weight loss | Round, moon-like face, slow speech, weight gain, cold intolerance, constipation |
Medical Screening and Dermoscopy at Haute-Derma
- Thyroid Biochemistry and Autoimmune Testing
- Serum TSH, FT3 and FT4 confirm biochemical hyperthyroidism.
- TRAb/TSI antibodies identify autoimmune Graves' disease (positive in > 95%).
- Skin Examination and Advanced Dermoscopy
- Dermoscopy of the shins (pretibial area): We look for pinkish-orange or grayish-brown myxedema plaques with rough skin and enlarged pores that give a "peau d'orange" (orange-peel) look.
- Onychoscopy: We assess the line of separation in Plummer's nails and rule out secondary fungal infection (onychomycosis).
- Trichoscopy: We look for signs of telogen effluvium (many follicles holding a single hair, short new anagen regrowth, no areas of follicular scarring).
- Eye Assessment and Lid Retraction Signs
- We check for Dalrymple's sign (upper lid retraction exposing the sclera) and von Graefe's sign (upper lid lagging behind the eyeball on downward gaze) to detect Graves' eye disease.
Combined Endocrine and Aesthetic Skin Management at Haute-Derma
Patients with hyperthyroidism need their hormone levels controlled before undergoing intensive dermatologic or aesthetic treatments:
Medical Thyroid Treatment (The Endocrine Foundation)
- Antithyroid drugs: thiamazole (methimazole) or propylthiouracil (PTU) inhibit thyroid peroxidase (TPO) and block T3 and T4 synthesis.
- Beta-blockers: propranolol controls a rapid heart rate, reduces hand tremor and inhibits peripheral conversion of T4 to T3.
Aesthetic Repair of Skin, Nails and Hair at Haute-Derma
Once thyroid levels are stable (euthyroid state), Haute-Derma offers treatments to restore appearance:
- Treating Pretibial Myxedema:
- Intralesional corticosteroid: triamcinolone acetonide 5–10 mg/mL is injected in small amounts directly into the firm plaques to stop fibroblasts producing hyaluronic acid.
- Compression therapy: compression stockings worn after injections help lymphatic drainage and reduce swelling.
- Controlling Excess Sweating and Facial Flushing: Micro-injections of botulinum toxin A (50–100 units) to the face or palms block acetylcholine release at eccrine sweat glands and calm the superficial blood vessels.
- Restoring Hair After Telogen Effluvium:
- Meso-Hair electroporation delivers growth peptides, biotin and PRP/PRF (platelet-rich plasma/fibrin) to nourish the follicles.
- Low-level laser therapy (LLLT) at 656 nm encourages follicles to re-enter the anagen phase sooner.
- Repairing Plummer's Nails: We clean the nail bed, trim away the lifted nail, apply topical antifungal/antibacterial solutions and use a keratin-enriched serum to strengthen the nail plate.
