Treating A Patient With Pruritic, ‘Swollen’ Legs
The last new patient of the clinic session presented in moderate distress with extremely pruritic legs. She was 74 years old and accompanied by her husband. The patient complained of swollen legs and itchy sores that had failed to resolve with previously prescribed mometasone cream. She had seen multiple doctors and was frustrated that her legs were becoming worse.
Her past medical history included type 1 diabetes, hypertension and hyperlipidemia. She had major polypharmacy with 11 medications to control the big three diseases (hypertension, hyperlipidemia and diabetes) as well as early cognitive impairment, anxiety and gastroesophageal reflux disease.
The examination revealed that the patient’s legs were studded with erythematous papules and excoriated hyperpigmented plaques. However, no cellulitis was evident. Mild pitting edema was present. There were about a dozen ulcerated plaques with yellow bases about both lower legs, especially laterally and posteriorly. The pedal pulses were obscured by lymphedema while the feet were clear of any lesions. The vibratory threshold at the hallux interphalangeal joint was five out of 18 seconds bilaterally, which was consistent with moderately severe peripheral sensory neuropathy.
Although the patient complained of leg “swelling,” the calf and ankle circumferences were not disproportionate. The sensory neuropathy may help to explain that her “swelling” complaint was actually dysesthesias.
Key Questions To Consider
1. What questions should a physician ask the patient?
2. What is the diagnosis?
3. What factors can cause pruritus?
4. What are the four areas of consideration that can limit the differential diagnosis?
5. What is the proper treatment?
Answering The Key Diagnostic Questions
1. “Have you or anyone in your family ever had food allergies, hay fever, asthma or skin rashes?”
3. Stress, atopic diathesis, anxiety, depression
4. Consider your primary first impression, mimicking conditions, the worst case scenario and more obscure condition possibilities.
5. Replenish the local depletion of cortisol with topical corticosteroids, central sedation to suppress the itch-scratch cycle and prevent further lesion aggravation with protective dressings.
A Closer Look At Neurodermatitis
Patients often complain of itching but are reluctant to admit actual scratching. Many conditions in the lower extremity have a pruritic component. These conditions include inflammatory tinea, neurodermatitis or even cutaneous T-cell lymphoma.
Why do some skin conditions itch? The free nerve endings in the skin trigger withdrawal from noxious stimuli while minor stimulation initiates reflexive touching and rubbing. Stronger stimulation produces pain. These sensations transmit from both myelinated and unmyelinated fibers. Both pain and itch follow the spinothalamic tracts but by different pathways.1 Individual thresholds vary.
Atopic diathesis predisposes patients to pruritus. It normally takes 200 firm strokes to produce a skin rash in patients without atopy while patients with atopy have cutaneous hypersensitivity and develop a rash with only 20 strokes. General atopy is quite common, affecting 7 percent of the adult population.2 One can readily detect the likelihood of atopic eczema by asking patients if they or anyone in their family ever had food allergies, hay fever, asthma or skin rashes.
In cases with a psychogenic component, anxiety and depression are often the primary triggers of neurodermatitis. Excessive stress can cause a variety of symptoms in patients. Individuals may respond to excessive stress with headache, gastrointestinal symptoms or skin reactions. Detecting and mitigating the stressor is an important step in determining the diagnosis and developing a comprehensive management plan.