Prurigo nodularis (PN), also known as prurigo nodular , is a skin disease characterized by pruritic (itchy) nodules that usually appear on the arms or legs. Patients often present with multiple multiporiation lesions caused by scratches. PN is also known as Hyde prurigo nodularis, Picker nodule , an atypical nodular form of circumscripta neurodermatitis, lichen corneus obtusus.
Lichen simplex chronicus is a different clinical entity.
Video Prurigo nodularis
Signs and symptoms
- Nodules are discrete, generally symmetrical, hyperpigmented or purpura, and hard. They are larger than 0.5 cm in width and depth (compared to papules less than 0.5 cm). They can appear in every part of the body, but generally begin on the arms and legs.
- Lesions that are experiencing the excoriation are often flat, umbilicated, or have crusty peaks.
- Nodules may appear in hair follicles.
- The nodule pattern may be a follicle.
- In true prurigo nodularis, nodules are formed before itching starts. Typically, these nodules are very itchy and only reduced by steroids.
Maps Prurigo nodularis
Cause
The cause of prurigo nodularis is unknown, although other conditions may cause PN. PN has been associated with Becker nevus, linear IgA disease, autoimmune conditions, liver disease and T cells. Systemic pruritus has been associated with cholestasis, thyroid disease, polycythemia rubra vera, uraemia, Hodgkin's disease, HIV and other immunodeficiency diseases. Internal malignancy, liver failure, kidney failure, and psychiatric illness have been considered to cause PN, although more recent studies have disproved the cause of psychiatry for PN. Patients report ongoing battles to distinguish themselves from those with psychiatric disorders such as delusions of parasitosis and other psychiatric conditions.
Pathophysiology
Chronic scratching and recurring, picking, or rubbing the nodules can cause permanent changes to the skin, including nodular lichenification, hyperkeratosis, hyperpigmentation, and skin thickening. Lesions that are not healed and experienced in the excoriation are often scaly, crusty or scabbed. Many patients report a lack of wound healing even when medications relieve itching and scratching.
Patients often:
- seek treatment during middle age, although PN may occur at any age.
- have a history of chronic heavy pruritus.
- has a significant medical history for unrelated conditions.
- suffer from hepatic or kidney dysfunction.
- suffers from secondary skin infections.
- have a personal or family history with atopic dermatitis.
- has other autoimmune disorders.
- have low vitamin D levels.
Diagnosis
The diagnosis is based on visual examination and the presence of itching. Skin biopsy is often done to rule out other diseases. A lesion biopsy will usually show high levels of eosinophils in PN. Cultures of at least one lesion will rule out staphylococcus infection, which is significantly associated with atopic dermatitis.
Treatment
Prurigo nodularis is very difficult to treat, but current therapies include steroids, vitamins, cryosurgery, thalidomide and UVB rays. In the case of staphylococcus or other infections present, antibiotics have proven to be effective, but tend to cause more damage than is good for this particular disease. A doctor may give a strong dose of prednisone, which will immediately stop the cycle of itching. However, steroid cessation allows relapse to occur, usually within a few weeks. Horiuchi et al recently reported a significant increase in PN with antibiotic therapy.
Another medicine that doctors may give is Apo-Azathioprine. Azathioprine, also known by its brand name Imuran, is an immunosuppressive drug used in organ transplants and autoimmune diseases and includes a purine analog chemistry class.
History
Prurigo nodularis was first described by Hyde and Montgomery in 1909.
See also
- Pruritus
- Skin lesions
Note
External links
situs
- DermNet NZ: Prurigo nodularis
- DermAtlas -2016053621
Source of the article : Wikipedia
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