Key signs and symptoms that differentiate an ingrown toenail from other foot conditions include localized pain at the nail border, redness, swelling, and sometimes infection with pus discharge. The pain is typically sharp and worsens with pressure or tight footwear, specifically at the lateral or medial edge of the toenail, distinguishing it from more diffuse foot pain seen in other conditions NICE NG19. Visible nail edge digging into the surrounding skin is a hallmark sign, often accompanied by granulation tissue formation in chronic cases. This contrasts with fungal infections or calluses, which do not present with a nail edge penetrating the skin Khunger & Kandhari 2012. Unlike diabetic foot ulcers or neuropathic lesions, ingrown toenails usually have a clear mechanical cause related to nail shape or improper trimming, and the inflammation is localized rather than widespread. The absence of systemic signs such as fever also helps differentiate uncomplicated ingrown toenails from more severe infections NICE NG19.
In summary, the combination of localized sharp pain at the nail border, visible nail penetration into the skin, associated swelling, redness, and possible pus discharge are key clinical features that distinguish ingrown toenails from other foot conditions.