My son's nails havent been growing at all for the last 5 years, not on his hands or feet. What could be causing this, and what kind of treatment can help his nails start growing again?

Nail growth arrest for 5 years may indicate an underlying condition, such as hypothyroidism, anemia, nutritional deficiencies (biotin, vitamin B12, or iron), skin conditions (psoriasis, eczema), or genetic disorders (nail-patella syndrome); potential complications include increased risk of fungal or bacterial infections, nail bed inflammation, or secondary infections; consult a pediatrician or dermatologist for a thorough evaluation