What are the aims of this leaflet? 

This leaflet has been written to help you understand more about nodular prurigo. It tells you what it is, what causes it, what can be done about it and where you can find more information.

What is nodular prurigo? 

‘Pruritus’ is the word doctors use for itching. ‘Prurigo’ is a word, which describes the changes in the skin after it has been scratched for a long time. In nodular prurigo, these changes look like firm, very itchy bumps (nodules) on the skin’s surface. These bumps can improve or resolve when the person stops scratching the area. However, for many people this can be very difficult without proper and sometimes prolonged medical treatment.

What causes nodular prurigo? 

The exact cause of nodular prurigo is unknown. It is a complex skin condition thought to have many different  and sometimes overlapping causes which can be physical and/or neuropsychological. For example, both heat and anxiety have been associated with nodular prurigo. However, it is difficult to determine their exact relationship with the condition. Heat can physically trigger itching, but it is not specifically a cause of nodular prurigo. However, reducing heat and sweating can also reduce itching and therefore, the symptoms of nodular prurigo. Similarly, stress can both trigger and be caused by nodular prurigo, but it is unclear why and how. However, we know that once the skin has become itchy, scratching and rubbing will cause the skin nerve endings to become thicker, more inflamed and cause further itching – this “scratch-itch” cycle can greatly worsen the condition.

• Nodular prurigo can start after an insect bite in some people.
• People with prolonged periods of stress are more likely to scratch and stress can make nodular prurigo worse.
• There is a strong association with atopy, i.e., having asthma, eczema and hay fever in people with nodular prurigo.
• There are several other medical and neuropsychological conditions that can be associated with nodular prurigo that may need to be further investigated and or discussed with your doctor(s) (see BAD leaflet on pruritus).

Is nodular prurigo hereditary? 

No, but atopy (allergic conditions) can run in families and is associated with nodular prurigo.

What does nodular prurigo look and feel like? 

Many hard, intensely itchy, bumps appear on the skin. They can appear anywhere, but the outside of the arms and legs are commonly affected. However, the back, buttocks, shoulders, and chest can also be affected, with the face rarely being involved. The mid-upper back is usually spared, this is known as the “butterfly sign”.

The nodules are usually darker than the skin around them but can also be lighter, flesh coloured, red or pink, depending on the individual’s skin type. The bumps have a rough, thick surface and may have a scab, crust, or scratch marks on top. The bumps are usually less than 1cm in diameter and can feel firm, tender and itchy. Some areas of skin can break down to form an ulcer.

Additionally, there may be some changes in the pigmentation of the skin and scars may develop in the affected areas from deep scratching. Nodular prurigo can occur at any age, and in any racial group or gender.

The itching caused by nodular prurigo 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.

How is nodular prurigo diagnosed?

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 healthcare professional can carry out a skin biopsy (cutting a section of one of the bumps under a local anaesthetic 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.

Can nodular prurigo be cured? 

No. The treatments for nodular prurigo focus on controlling the condition. Nodular prurigo can gradually improve over time, although this can take months or years for some people. Affected individuals are advised not to scratch or rub the nodules to help break the “scratch-itch” cycle, but this can be very challenging. Some ways to help break this cycle and treat the areas are explained below. 

How can nodular prurigo be treated?

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

• Topical corticosteroids. Your healthcare provider may prescribe a potent (or strong) steroid cream or ointment that will help reduce the inflammation in the skin. A very potent (or very strong) steroid will help relieve itch. Topical corticosteroids should be applied as instructed by your prescribing healthcare professional.
• Tacrolimus 0.1% ointment. This treatment can have anti-inflammatory effects to help decrease itching and does not contain steroids.
• Paste bandages or cling-film. Covering the affected skin on top of the steroid with a paste bandage or cling film can increase the effect of the steroid. This is useful when the condition is very itchy or flaring. It also creates a physical barrier that protects your skin from scratching it too hard.
• Emollients. It is very important to stop using soaps, shower gels, or other cosmetics to wash with as they can lead to dry skin. A fragrance-free emollient should be used instead of soap and rinsed away. It is equally important to apply emollients regularly, at least twice, throughout the day as a moisturiser. This helps maintain good skin health as the skin of people affected by nodular prurigo may be drier than usual. As such, emollients can help in several ways. Firstly, they moisturise the skin, which may help ease dryness and itching. They can also reduce scaling and soften cracked areas of skin. Lastly, they also help topical treatments (such as steroids) work better, by allowing them to penetrate the skin better.
• Antihistamine tablet or syrups. These can help relieve the feeling of itch. Non-sedative antihistamines, such as fexofenadine or cetirizine are best. Sedative antihistamines may produce adverse health problems if used long-term.
• Phototherapy. Some examples include narrowband UVB phototherapy and psoralen and UVA phototherapy. These treatments normally take place in the hospital 2-3 times a week over the course of usually 2-3 months. UV light treatment can reduce the number of nodules, prevent the appearance of new ones, and reduce the sensation of itch.
• Psychological treatment. Symptoms of pain and itch related to nodular prurigo can be very distressing. People affected by this may benefit from psychological support or medication. These can help relieve stress, anxiety, depression, low mood, or nerve related (neuropathic) itch or pain. Please discuss this with your healthcare professional.
• Immune-suppressing treatments. If the above treatments have not been helpful, or the nodular prurigo is very severe or because of other reasons these can be prescribed. These treatments aim to reduce inflammation and include the following:
• Oral corticosteroids (short-term only)
• Ciclosporin
• Methotrexate
• Azathioprine

It is important to note that these treatments can cause side effects. Because of this, you will need regular monitoring with blood tests and clinic appointments.

Currently, newer treatments are being assessed for treating nodular prurigo on the NHS and might be available in the near future.

Self-care (What can I do?) 

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

• Anything you can do to take your mind off the itch will help to reduce or stop the scratching, like distraction techniques or keeping the hands occupied or wearing mittens / cotton gloves to reduce scratching especially at night.
• You may find that laying a cool damp flannel on the skin can reduce the feeling of itch. A cooled emollient which has been kept in the refrigerator, or has added menthol, may also help.
• Keep the temperature in your bedroom cool (18-20°C) and use light and breathable bedclothes. If you feel hot and itchy during the day, a fan can help to cool the skin down. If possible, discuss work adjustments with your employer.
• Wearing layers of cotton clothing can be better than heavy, scratchy, or synthetic fabrics. It is advisable to avoid wool or polyester clothing. These materials do not absorb sweat as easily, leading to overheating and itching. For more information on how to care for itchy skin, visit https://www.nhs.uk/conditions/itchy-skin/

Where can I get more information?

Web links to detailed leaflets:

http://patient.info/doctor/prurigo-nodularis-pro

www.dermnetnz.org/dermatitis/prurigo-nodularis.html

https://www.aad.org/public/diseases/a-z/prurigo-nodularis-self-care

Jargon Buster: https://www.skinhealthinfo.org.uk/support-resources/jargon-buster/

Please note that the BAD provides web links to additional resources to help people access a range of information about their treatment or skin condition. The views expressed in these external resources may not be shared by the BAD or its members. The BAD has no control of and does not endorse the content of external links.

This leaflet aims to provide accurate information about the subject and is a consensus of the views held by representatives of the British Association of Dermatologists: individual patient circumstances may differ, which might alter both the advice and course of therapy given to you by your doctor. 

This leaflet has been assessed for readability by the British Association of Dermatologists’ Patient Information Lay Review Panel

BRITISH ASSOCIATION OF DERMATOLOGISTS PATIENT INFORMATION LEAFLET

PRODUCED | AUGUST 2004

UPDATED | MAY 2010, MAY 2013, MAY 2016, JANUARY 2020, JULY 2023

NEXT REVIEW DATE | JULY 2026