Prurigo

Prurigo refers to the group of skin disorders presenting intensely pruritic and often difficult to treat nodules or papules on the skin. One of the conditions well known is called nodular prurigo which are the changes that occur in the skin after it has been itched and scratched for a period of time. Other types include prurigo simplex which is the symmetrically disturbed, dome-shaped bumps, prurigo pigmentosa characterized by the net-like pigmentation and nodular prurigo presenting as hard warty nodules. The changes associated with prurigo present themselves are hard and itchy lumps. Among the affected individuals, the itching can be very intense which is made worse by sweating or heat resulting in people scratching themselves to the point of bleeding. In some cases, the affected individual could also have other diseases such as HIV infection, severe anemia, lymphoma or kidney disease. The exact cause of this condition is not known and what causes the itchiness in the initial place also remains unclear. When individuals have a skin biopsy, the nerves on the skin often appears to be thickened. This could result in sending the strong signals to the brain that the skin is itchy causing the nerves to become even more thickened. This itch-scratch cycle, therefore, increases the number of nodules on the skin making the condition worse.

What does it look like?

Several hard bumps darker than the surrounding skin could become apparent which are often very uncomfortable. These bumps have a rough, thickened surface with scratch marks on top. These bumps are usually less than 1 cm in diameter and may be firm, tender, crusty and itch. The most commonly affected parts of the body are the back, buttocks, shoulders and the chest. It generally affects individuals between 20 and 60 years of age of both the sexes and any race.

Investigations and Management

The condition is suspected based on the physical appearance and in atypical case, a skin biopsy will be required to confirm the diagnosis. Further tests may also be required based on the results of the initial screens.

The treatment of nodular prurigo is based on providing relief from the symptoms and to stop the itching of the skin. The treatments are;

  • A steroid cream to help reduce the inflammation in the skin
  • Covering the skin with an ointment or a paste bandage can also help reduce the itching and damage to the skin
  • An antihistamine medication could reduce the itching but can cause drowsiness
  • Ultraviolet light treatment administered at the hospital can reduce the number of nodules and the new nodules from developing
  • In case of severe cases causing distress, immune-suppressing treatment can help reduce inflammation

Even though the treatment can help to relieve the symptoms, most of the affected individuals do not have a complete resolution of the nodules. As it can affect the quality of life such as sleeping habits, it may result in stress and depression. Therefore, it is important to talk to the health care provider if signs of depression become evident.

References

https://www.dermnetnz.org/topics/prurigo/

http://www.pcds.org.uk/clinical-guidance/nodular-prurigo

https://rarediseases.info.nih.gov/diseases/7480/prurigo-nodularis

https://www.aocd.org/page/prurigonodularis