You can estimate the body surface area by the Rule of 9's. The percentage of the body involved can be calculated as follows:
Head = 9%chest (front) = 9%abdomen (front) = 9%Upper/mid/low back and buttocks = 18%Each arm = 9% (front = 4.5%, back = 4.5%)Groin = 1%Each leg = 18% total (front = 9%, back = 9%)Although the feet aren't shown, the body surface area of the entire front of a leg is 9%, so a foot is obviously less than half, or even a third of that. In addition, athlete's foot normally does not encompass the entire foot, therefore making the percentage even less.... Like 1-2%, which equates to a 0%. It would be nearly impossible to get a 10% evaluation off of the feet alone, as the percentage of total body, or exposed body is just too small.
7813 Dermatophytosis (ringworm: of body, tinea corporis; of head, tinea capitis; of feet, tinea pedis; of beard area, tinea barbae; of nails, tinea unguium; of inguinal area (jock itch), tinea cruris):
Rate as disfigurement of the head, face, or neck (DC 7800), scars (DC's 7801, 7802, 7803, 7804, or 7805), or dermatitis (DC 7806), depending upon the predominant disability.
Since you have a problem with your feet, we can rule out 7800 as a diagnostic code, as this is not the head, face or neck. You can be rated under scars (DC 7801,7802, 7803,7804,7805), or dermatitis (DC 7806). Most of the ratings that I have done were 0%, however, if you have dermatitis, eczema, or other skin issues that are service connected, on top of the athletes foot, the chances are, you will have a higher the percentage of exposed body or total body area affected, hence a 10%, or maybe even 20% disability evaluation. The creams that you said you were taking constitute topical therapy. However, you stated that you take medications as well, and without knowing the names of those medications, I am unable to determine whether they are systemic therapy such as corticosteroids, or other immunosupressive drugs. What are you, or have you been taking?