What role does TSH play in Haut?

TSH (thyroid-stimulating hormone) primarily regulates thyroid function and indirectly affects skin via T3/T4. In hypothyroidism (high TSH), skin often becomes dry, coarse, and pale; in hyperthyroidism (low TSH), skin is moist, warm, and thin. Direct TSH effects on skin cells (e.g., via TSH receptors in hair follicles) are mechanistically plausible but clinically minor. Evidence is human-moderate: based on observational studies and mechanistic data. A single TSH value without free thyroid hormones is insufficient for skin assessment. Caveat: skin changes are nonspecific; always consider other causes and consult a clinician.