What causes a hollow or missing area under the toenail?

Generally, a hollowed-out area in the toenail may be caused by aging, trauma, infection, onychomycosis, or psoriasis. It is recommended to seek medical attention promptly, identify the underlying cause, and receive symptomatic treatment under the guidance of a qualified physician. Specific analyses are as follows:

1. Aging

As people age, toenail growth slows down, and the nail plate may gradually become thinner, sometimes resulting in localized hollow areas. Maintaining good personal hygiene, regularly trimming toenails, and avoiding tight-fitting shoes can help reduce pressure on the nails.

2. Trauma

External force can damage the connective tissue between the nail bed and the nail plate, leading to separation of the nail plate from the nail bed and creating a hollow area in the toenail. Keeping the injured area clean and preventing infection is important; minor injuries may heal on their own.

3. Bacterial Infection

Bacterial infections typically occur when bacteria enter the body and infect the toenail, disrupting the structure of the nail plate and potentially causing separation of the nail from the nail bed, resulting in a hollow section. Symptoms may also include discoloration, thickening, and brittleness of the nail. Patients may use medications such as ketoconazole cream, terbinafine hydrochloride cream, or miconazole nitrate cream as directed by a physician.

4. Onychomycosis (Fungal Nail Infection)

Onychomycosis is a fungal infection caused by dermatophytes. Molds can enter the inner layers of the nail through cracks or the base of the toenail. After infection, changes in nail color may occur, gradually expanding into areas of detachment, ultimately causing a portion of the toenail to become hollow. Symptoms may include nail thickening, deformation, and fragility. Under medical supervision, patients may use medications such as itraconazole capsules, terbinafine hydrochloride tablets, or ciclopirox olamine cream for treatment.

5. Psoriasis

Psoriasis is an autoimmune disease triggered by environmental and genetic factors. Abnormal immune responses may lead to inflammatory reactions in the toenail bed and nail matrix, disrupting the normal nail growth structure and causing the aforementioned symptoms. Other symptoms may include skin redness, scaling, and joint pain. Treatment should follow medical advice and may include topical medications such as halometasone cream, mometasone furoate cream, or tretinoin cream.

Maintain a healthy diet by avoiding spicy and irritating foods, and engage in regular exercise to strengthen the body's immune system.