Cellulitis: This is a common condition characterized by redness, swelling, and sometimes warmth of the skin, often caused by bacterial infection. The great toe is a frequent site due to its susceptibility to trauma and infection, making cellulitis a plausible explanation for reoccurring erythema in this area.

Gout: Gouty arthritis can cause recurrent episodes of erythema, especially in the great toe, due to the deposition of urate crystals. The pain and inflammation associated with gout can lead to erythema.
Ingrown Toenail: An ingrown toenail can cause erythema, swelling, and pain, especially if it becomes infected. This condition is common and can recur if not properly managed.
Eczema/Dermatitis: Eczema or dermatitis of the foot can cause erythema and may recur due to various triggers such as allergens, irritants, or stress.

Osteomyelitis: Although less common, osteomyelitis (bone infection) can present with erythema and should not be missed due to its potential for serious complications if left untreated.
Deep Vein Thrombosis (DVT): While DVT typically presents with swelling and pain in the leg, erythema can be a part of the clinical picture. It's crucial to consider DVT due to its risk of pulmonary embolism.
Diabetic Foot Infection: In patients with diabetes, foot infections can be severe and may present with erythema. Early recognition is critical to prevent serious complications.

Erythromelalgia: A rare disorder characterized by burning pain, heat, and redness in the hands and feet. It could be considered in the differential for reoccurring erythema, especially if other symptoms are present.
Complex Regional Pain Syndrome (CRPS): Although rare, CRPS can cause erythema among other symptoms like pain and swelling, usually following an injury.
Lymphoma: Cutaneous lymphomas can present with skin lesions, including erythema, and while rare, they should be considered in a differential diagnosis to ensure no serious conditions are overlooked.