10 Nail Changes That May Indicate an Underlying Health Issue

6. Pitting and Nail Psoriasis - Autoimmune Manifestations

Nail pitting appears as small, punctate depressions scattered across the nail surface, resembling the surface of a thimble or the skin of an orange. These tiny holes or dents in the nail plate result from localized defects in nail formation within the nail matrix, where inflammatory processes disrupt the normal keratinization process. Nail pitting is most commonly associated with psoriasis, affecting approximately 50% of individuals with this autoimmune skin condition, and up to 80% of those with psoriatic arthritis. The pitting pattern in psoriasis can vary from fine, superficial depressions to deeper, more irregular holes, and may be accompanied by other nail changes such as onycholysis (nail separation), subungual hyperkeratosis (thickening under the nail), and oil drop discoloration. Beyond psoriasis, nail pitting can also occur in other autoimmune and inflammatory conditions including alopecia areata, where it may affect up to 46% of patients, eczema, lichen planus, and reactive arthritis. The severity and pattern of pitting can sometimes help differentiate between these conditions, with psoriatic pitting typically being more irregular and deeper compared to the fine, uniform pitting often seen in alopecia areata. In some cases, nail pitting may be the first or only manifestation of psoriasis, appearing years before skin lesions develop. The presence of nail pitting, especially when accompanied by joint pain, skin changes, or hair loss, should prompt evaluation for underlying autoimmune conditions, as early diagnosis and treatment can help prevent progression and complications.