What does prurigo look like?
The elements are dense nodules ranging in size from a few millimeters to one and a half to two centimeters, the skin over them is often thickened, with a crust or abrasion in the center from scratching. The color varies from pink to dark brown, especially in people with dark skin. The rashes are located symmetrically where it is easy to reach with your hand, and typically spare the central part of the back, which a person cannot comb. Over time, the skin between the nodules becomes rougher, the skin pattern intensifies, and dark spots and scars remain.
- Dense knots with combed tops
- Symmetrical arrangement on arms, legs, back
- The out-of-reach area on the back remains clear
- Thickening of the skin between the elements
- Dark spots and scars after healing
- Severe itching, worse in the evening
Reasons and what to look for
Prurigo is not a final diagnosis, but a signal to look for the source of the itching. In some patients, this is a manifestation of atopic dermatitis or severe dry skin. For others, internal diseases are behind the itching: chronic kidney disease, liver disease with bile stagnation, diabetes mellitus, thyroid disorders, iron deficiency, and, less commonly, lymphoma and other blood diseases. Nervous factors play a role: nerve damage from diabetes and shingles, as well as chronic stress and anxiety. Sometimes the trigger is insect bites or scabies.
- Atopic dermatitis and dry skin
- Chronic kidney disease
- Diseases of the liver and biliary tract
- Diabetes mellitus
- Thyroid dysfunction
- Iron deficiency
- Parasitosis and scabies
- Side effects of drugs
Survey
The diagnosis of prurigo itself is made upon examination by the characteristic appearance of the elements. Most of the time is spent searching for the cause of the itching. The standard set includes a general blood test, biochemistry with liver and kidney parameters, glucose, TSH and ferritin. If parasites are suspected, appropriate tests are prescribed; if scabies is suspected, an examination with a search for burrows is prescribed. If the rash is atypical or does not respond to treatment, a skin biopsy is performed. In older people with itching all over the body, the doctor must rule out blood diseases.
- General blood test
- Biochemistry: liver function tests, creatinine
- Blood glucose and glycated hemoglobin
- TSH
- Ferritin
- Examination for parasites
- Skin biopsy for an atypical picture
How to break the cycle of itching
While a person is scratching his skin, no treatment will give a lasting result. Therefore, the practical part is important: short-cut nails, cotton gloves at night, cool showers instead of hot ones, avoidance of hard washcloths and aggressive soaps. Applying liberal amounts of emollients several times a day reduces dryness and itching. Cooling compresses and menthol products prescribed by a doctor help. It is worth removing provocateurs: overheating, woolen fabrics on a naked body, alcohol and spicy foods if you are prone to hot flashes.
- Short nails, gloves at night
- Cool short shower, gentle cleansing
- Emollients 2–3 times daily
- Cooling compresses
- Cotton loose clothing
- Stress control, if necessary, help from a psychologist
Treatment
The treatment is selected by a dermatologist, and it is always two-component: an effect on the skin and correction of the underlying cause. External anti-inflammatory agents are used on the skin, including a course of topical glucocorticoids and calcineurin inhibitors, sometimes under an occlusive dressing for dense nodes. For common forms, phototherapy is used. The doctor may prescribe systemic drugs that affect the transmission of the itching signal, and in case of severe persistent disease, modern immunobiological drugs. Antihistamines do not help everyone, since itching with prurigo is associated not only with histamine.
- External glucocorticoids in a course as prescribed by a doctor
- Calcineurin inhibitors
- Phototherapy
- Systemic medications to control itching
- Treatment of the underlying disease
- Treatment of infected scratches
- Refusal of independent long-term use of hormonal ointments