A raised horizontal ridge on the thumb nail cap may be caused by chronic onychomycosis, nail psoriasis or trauma.
1. Chronic onychomycosis: It may be related to Candida or long-term repeated exposure to irritants or mutagens, and the patient’s nails will show discoloration and bulging, etc. Therefore, chronic onychomycosis may be the cause. Therefore, a horizontal ridge protruding from the nail cap of the thumb may be chronic onychomycosis.
2. Nail psoriasis: Nail psoriasis is mainly caused by the extension of psoriasis lesions to the nails, and the nails will appear depression, separation, longitudinal ridge, transverse groove and other changes. Therefore, a raised horizontal ridge on the nail cap of the thumb may be nail psoriasis.
3. Trauma: If the nail has been previously subjected to external pressure and impact, then the nail bed will be damaged, and there will be a raised horizontal ridge after repair. Therefore, a raised horizontal ridge on the thumbnail cap may also be caused by trauma.
There are many other factors that can cause a raised horizontal ridge on the thumbnail, so it is recommended that patients go to a regular hospital for examination and treatment under the correct guidance of the doctor, so as not to delay the condition.