Hello doctor, I have noticed thickening of the skin on the right toe which is a little darker than the rest of the skin. There is no irritation, or any other issue. I have been applying moisturizer to keep it softer. What are the cause and remedy? I am a diabetic aged 52 years and diabetes is under control with medication. HbA1c was 6.7 % 20 days back.
Hi. Since how many months you have noticed this? Do you have similar lesions anywhere else? Knuckle? Neck? Possibilities are frictional hyperkeratosis or acanthosis nigricans. Most likely it is frictional hyperkeratosis, could be friction from the footwear, since it is localized and involves single toe as per the picture (attachment removed to protect patient identity). The other possibility is acanthosis nigricans, thickening, and darkening of skin over the neck, armpits, knuckle, toes, common in diabetes.  Frictional hyperkeratosis responds to topical corticosteroids with Salicylic acid combination ointment, like HH Salic ointment, mix it with Xerina cream (moisturizer with Urea and Glycolic acid, helps to smoothen and lighten the skin) in 1:1 ratio. Apply a thin layer to the affected spot only at night. Make sure not to apply on the normal skin. Use it for two weeks. Use soft footwear that does not put pressure on the toe.