However, new patches may appear as older ones resolve, making a prolonged duration fairly common. In extreme cases, all nails may be shed, making it difficult for the patient to pick up small objects. If nail changes are seen with patchy alopecia, the possibility for extensive hair loss may be increased. When hair loss involves eyebrows, eyelashes, or nostril hairs, other physical problems may result. Sweat from the forehead may fall into the eyes if the eyebrows are lost.
Eyelashes protect the eyes from foreign objects, and nostril hairs filter air and remove debris.
Without these protective hairs, other sequelae may ensue. In patients who have alopecia areata, pigmented hairs tend to fall out more easily than nonpigmented ones. Thus, if a mixture of pigmented and nonpigmented hairs is present, the hair could appear to turn white overnight. Interestingly, initial hair regrowth is often also nonpigmented, only to be followed by return of pigment production after variable periods of time. When there is doubt about the diagnosis, findings from a 4-mm punch biopsy may be helpful.