Differential Diagnosis for Cutaneous Lesion on Feet
Single Most Likely Diagnosis
- Tinea Pedis (Athlete's Foot): This is a common fungal infection of the foot, characterized by itching, scaling, and cracking of the skin. It's often seen in individuals who wear tight shoes, use public showers, or engage in sports that involve sweating.
Other Likely Diagnoses
- Plantar Warts: Caused by the human papillomavirus (HPV), these are small, rough growths on the bottom of the foot that can be painful.
- Eczema (Dyshidrotic Eczema): A condition characterized by small, itchy blisters on the feet, often related to stress, allergies, or environmental factors.
- Psoriasis: An autoimmune condition that can cause red, scaly patches on the feet, among other areas of the body.
- Contact Dermatitis: A skin reaction that occurs after contact with an irritant or allergen, leading to redness, itching, and small blisters.
Do Not Miss Diagnoses
- Malignant Melanoma: Although less common, any new or changing skin lesion, especially those that are asymmetric, have irregular borders, color variation, diameter larger than 6mm, or are evolving, should be considered for melanoma due to its high mortality rate if not caught early.
- Deep Vein Thrombosis (DVT): While not a skin condition per se, DVT can cause skin changes such as redness, warmth, and swelling in the affected leg and foot, and is a medical emergency due to the risk of pulmonary embolism.
- Cellulitis: A bacterial skin infection that can cause redness, swelling, and warmth, often requiring antibiotic treatment to prevent serious complications.
Rare Diagnoses
- Keratoderma: A group of rare skin conditions that cause thickening of the skin on the palms and soles.
- Pitted Keratolysis: A bacterial infection that causes small pits in the skin of the feet, often associated with excessive sweating.
- Erythrasma: A bacterial or fungal infection that causes brownish-red patches in the folds of the skin, including between the toes.