Nodular Prurigo

‘Pruritus’ is the word doctors often use for itching. ‘Prurigo’ is a related word, which describes the changes that appear in the skin after it has been itched and scratched for a long time.

In nodular prurigo, these changes look like firm, very itchy bumps (nodules) on the skin’s surface. These can improve or resolve when the person stops scratching the area, although, for many people, this can be very difficult without proper and sometimes prolonged medical treatment.

It is not known what causes nodular prurigo or makes the skin react in this way. However, once the skin has become itchy, scratching and rubbing will cause the skin nerve endings to become thicker, more inflamed, and cause more itching, making the condition worse.

• Nodular prurigo may start after an insect bite in some people, for example.
• Individuals who have prolonged periods of stress are more likely to scratch. Stress can, therefore, make nodular prurigo worse.
• Up to 80% of people with nodular prurigo are atopic, i.e., may have asthma, eczema, hay fever, or other allergic conditions.
• Several other medical conditions may be associated with nodular prurigo that may need to be further investigated. 

No, apart from the fact that atopy (allergic conditions) runs in families and is associated with prurigo.

The itching can be very distressing physically and psychologically. In some cases, the itch can be so severe that it causes problems with sleep, work, relationships, and mood. 

The skin shows many hard bumps that are intensely uncomfortable and can appear anywhere on the body. They are usually darker than the skin around them. They have a rough, thick surface and may have a scab, crust, or scratch marks on top. 

The lumps are usually less than 1cm in diameter and can feel firm, tender, and itchy. Some areas of skin can breakdown to form an ulcer.

The lateral aspect or the sides of the arms and legs are the most commonly affected areas. However, the back, buttocks, shoulders, and chest can also be affected. The upper mid-back is usually spared. 

Nodular prurigo is most common between 20 and 60 years of age. It can present in any racial group and any gender, although it is seen most commonly in older women. 

Symptoms of itching and the typical skin lesions described above are usually enough to make the diagnosis of nodular prurigo. If there is any doubt, then your doctor can carry out a skin biopsy (cutting out one of the bumps under a local anesthetic and sending it to a pathologist to examine under a microscope; this can help to confirm the diagnosis.

Blood tests may be taken to check for other conditions that can make the skin itchy, e.g., iron-deficiency anemia, kidney or liver disease, vitamin D deficiency.

No. Nodular prurigo can be challenging to clear, but it can usually be controlled and should gradually improve over time, although this can take months or years in some patients. Affected individuals are advised not to scratch or rub the nodules, but in practical terms, this is very difficult, without proper treatment, as explained below.

The treatments for nodular prurigo are aimed at stopping the skin itching:

• A strong steroid cream or ointment.
• Covering the affected skin with paste bandages or cling-film on top of the steroid can increase the effect of the steroid on the skin. This covering is useful for when the condition is very itchy or flaring. It also helps to reduce scratching by creating a barrier.
• It is crucial to stop using soaps, shower gels, or other cosmetics to wash with as they can dry the skin.
• It is equally important to apply emollients regularly throughout the day (at least twice) as this helps maintain good skin health. 
• An antihistamine tablet or syrup can help to reduce the feeling of itching.
• Ultraviolet light treatment (narrowband UVB), given three times a week in the hospital for a treatment course lastly approximately 2-3 months,  can help to reduce the number of nodules, prevent new nodules appearing, and reduce the sensation of itch.
• Psychological support or medication to relieve stress, anxiety, or depression may be offered, as this can help with mood and some symptoms of itch.
• If nodular prurigo is very severe and the above have not been helpful, immune-suppressing treatments such as tablet steroids (short-term only), ciclosporin, methotrexate, or azathioprine can be prescribed to help reduce inflammation. It is important to note that these treatments may cause additional side effects and will need regular monitoring with blood tests and clinic appointments. 

The most important but most challenging thing to do is to stop scratching.

• Anything you can do to take your mind off the itching will reduce or stop the scratching.
• You may find that laying a cold damp flannel on the skin can reduce the feeling of itch. A cooled emollient (moisturizer), which has been kept in the refrigerator, may also help.
• Keep your bedroom cool, and do not sleep with heavy or heat retaining bedclothes. If you are hot and itchy during the day, a fan can help cool the skin down.
• Cotton clothing worn in layers can be better than heavier materials such as wool or synthetic products, which do not absorb sweat easily, leading to overheating and itching.