Heloma durum (hard corn): This is the most likely diagnosis given the description of hard corns on the bilateral pinky toes. The presence of an opening and tunneling without significant redness or purulent fluid suggests a deep-seated corn that has penetrated into the dermis, causing bleeding.

Heloma molle (soft corn): Although less likely than a hard corn due to the description, a soft corn could potentially present similarly, especially if it becomes macerated and forms a small sinus tract.
Verruca (plantar wart): Plantar warts can sometimes present with a central core or opening and may bleed if irritated. However, they are usually more painful and may have a characteristic cauliflower appearance.
Ingrown toenail: While the description does not specifically mention the toenail, an ingrown toenail could potentially cause similar symptoms if it penetrates deep into the skin and causes a reaction.

Osteomyelitis: Although the patient does not have a fever, and there's no mention of purulent fluid, osteomyelitis (bone infection) could present with localized signs of infection such as pain, swelling, and drainage. It's crucial to consider this diagnosis, especially if the patient has risk factors like diabetes or immunocompromised status.
Squamous cell carcinoma: This type of skin cancer can sometimes present as a non-healing ulcer or a lesion that resembles a corn or wart. The presence of bleeding and a sinus tract could be indicative of a more serious underlying condition.
Diabetic foot ulcer: In patients with diabetes, what appears to be a simple corn could actually be a foot ulcer, which can quickly become infected and lead to serious complications.

Keratoacanthoma: A rare, low-grade malignancy that can resemble a corn or wart but typically grows more rapidly.
Subungual exostosis: A benign bone growth under the toenail that could cause pain and potentially lead to the formation of a corn-like lesion if it irritates the surrounding skin.
Erythromelanosis follicularis faciei et colli (if the condition were to spread): Although this condition primarily affects the face and neck, it could theoretically cause similar skin changes on the toes, though this would be extremely rare and not directly related to the initial presentation of hard corns.