Pigmented Lesions & Pigmented Areas of Skin
Pigmented lesions should always be inspected and observed. Most pigmented areas are nothing but freckles and moles. However a potentially deadly pigmented lesion that can occur on the foot and lower extremity is Malignant Melanoma. A physician should evaluate any pigmented lesion that suddenly occurs or a pigmented lesion that starts to change its appearance. These changes are usually subtle and may consist of increased size and depth of color, onset of bleeding, seepage of clear fluid, tumor formation, ulceration and formation of satellite pigmented lesions. The color is usually not uniform but is likely to be scattered irregularity, being brown, bluish black or black. An increase in pigmentation may precede enlargement of the lesion by several months. Although any part of the body may be affected, the most frequent site is the foot, then in order of frequency, the remainder of the lower extremity, head and neck, abdomen, arms and back. Malignant melanoma may also form under the nails of the feet and hands. The thumb and big toe are more commonly affected than the other nails. Quite often the adjacent skin to the nail is ulcerated. Usually a fungal infection is suspected and antifungal treatment may be administered for months before the true nature of the lesion is discovered. A black malignant melanoma of the toe can also be mistaken for gangrene. Overall, the incidence of malignant melanoma is quite low.
Another cancer causing lesion that can occur on the feet are called Actinic Keratosis. Although most commonly found in sun-exposed areas of the body such as the face, ears, and back of the hands, these lesion can also occur on the foot. They are characterized as either flat or elevated with a scaly surface. They can either be reddish or skin colored. On the foot they are frequently mistaken for plantars warts. These lesions are the precursor of epidermoid carcinoma. Treatment for these lesions should be through as they are definitely precancerious. Treatment consists of freezing the lesions with liquid nitrogen or sharp excision.
Yet another cancerous lesion that can occur on the foot is called Kaposi’s Sarcoma. These lesions occur most commonly on the soles of the feet They are irregular in shape and have a purplish, reddish or bluish black appearance. They tend to spread and form large plaques or become nodular. The nodular lesions have a firm rubbery appearance. The appearance of these lesions is an ominous sign. In the late 1970’s and early 1980’s an outbreak of Kaposi’s sarcoma occurred in San Francisco, California. It was later learned that the disease was associated with AIDS infection. It can occur without the concurrent AIDS infection but this is very rare.
Chronic athlete’s foot can cause an increased pigmentation to the bottom of the foot. It is associated with dry scaling skin and may have a reddish appearance.
Achilles tendonitis generally responds very well to conservative treatment as long as it is diagnosed and treated early. Surgery is rarely indicated unless the Achilles tendonitis is particularly severe and chronic, or if the tendon has ruptured completely.
Initially, the podiatrist may treat the Achilles tendonitis by putting heel lifts into the patient’s shoes. In addition, the patient may be asked to avoid barefoot walking or walking in low-heeled shoes. Non-steroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen (Motrin, Advil) and naproxen (Naprosyn, Aleve) may also be prescribed to calm the inflammatory process in the tendon. Icing may be suggested to help decrease the inflammation and pain in the tendon. Stretching exercises for the calf muscles may also be given to the patient to help loosen the calf muscle and Achilles tendon so that the tendon is not under as much stress during normal daily walking activities. The stretching should not be done however if it causes pain in the Achilles tendon.
Initially, the patient with Achilles tendonitis will be asked to modify their activities to decrease their running and jumping activities and do alternative physical activities, such as swimming, which don’t put as much stress on the Achilles tendon. As the tendon starts to feel better, the podiatrist will allow a gradual return to normal running and jumping activities. If normal return to activities is not possible within a few weeks, then many times the podiatrist may additionally prescribe physical therapy and/or functional foot orthotics to help the tendon heal more rapidly. The foot orthotics generally are used during both the sports activities and walking activities to allow for more normal foot and Achilles tendon function. If the physician is concerned about a partial tear of the tendon the patient may be placed in a below the knee cast. It can take several weeks or even months for the tendon to heal depending upon the severity of the injury to the tendon. It is not uncommon for a patient to return to activities too quickly and re-injure the tendon. Careful monitoring of a return to full activity is important and the patient must have patience during this period of time.
Another cause of generalized increased pigmentation is diabetes. The condition termed Diabetic Dermopathy occurs most frequently on the shins and lower legs. They may have the appearance of small scars. Their appearance may precede the diagnosis of diabetes by several years. The actual cause of diabetic dermopathy is not well understood, but it does not cause any particular problem or pose any particular health threat.
Small, spider-like areas of increased pigmentation on the ankles are caused by the break down of small veins in the area and are called Spider Veins; they also pose no health risks.