Alles wat u moet weten over Prurigo Nodularis

Hoe ziet prurigo nodularis eruit?

Bij prurigo nodularis is er dus sprake van een huidaandoening, waarbij er vervelende jeukende bulten op de huid verschijnen. Deze bulten variëren in grootte, maar worden vaak niet groter dan één centimeter. Ze hebben een bolronde vorm en rode, paarse of zelfs bruine kleur. Als je aan de jeukende bulten zit, voelen deze vrij stevig aan. De omliggende huid is vaak rood, droog en geïrriteerd.

De jeukende huidaandoening kan over het hele lichaam voorkomen. Wel is het zo dat de hevig jeukende bulten meestal op de armen en benen zitten. Vooral op de polsen ziet de huidklacht er vaak wat heftiger uit. Mensen krabben hier vaak sneller en harder.

Wat bij prurigo nodularis ook opvalt, is dat wanneer er langdurig aan de huid gekrabd wordt, er nieuwe bulten ontstaan. Ook kunnen bestaande bulten weer wegtrekken, maar het blijft een chronische aandoening. Dit betekent dat prurigo nodularis nooit helemaal verdwijnt. Wel wisselen periodes van rust zich af met opvlammingen.

Treatment / Management

Management of PN requires a multifaceted approach. Patients need to be educated on practices to reduce scratching of lesions. Further, any psychological disorder associated with scratching and picking at skin should be diagnosed and treated. Any underlying causes of pruritus should also be diagnosed. Treatments for PN, both topical and systemic, are targeted at disrupting the itch-scratch cycle.

General Care

Patients with PN should be advised to:

Keep their nails short, wear protective clothing (ie, long sleeves and gloves), and keep the nodules covered with bandages.

Specific Care

Topical and Intralesional Therapy

Although none have been examined in randomized trials, topical treatments for PN include class I topical corticosteroids, intralesional corticosteroids, topical calcineurin inhibitors, topical capsaicin, and topical vitamin D analogs.

The suggested first-line therapy consists of topical corticosteroids, such as clobetasol dipropionate 0.05% ointment, applied under occlusion with plastic wrap once at nighttime for at least 2 to 4 weeks.

Triamcinolone acetonide, in concentrations of 10 mg/mL to 20 mg/mL injected intralesionally, has been shown to flatten lesions and provide relief from pruritus.[27][28][29][30][31]

Antihistamines and Leukotriene Inhibitors

Phototherapy and Excimer Laser

History and Physical

Lesions can often appear excoriated due to the pruritus involved with PN. Excoriated lesions are at increased risk of secondary infection and can appear crusted, erythematous, or painful if infected. PN can also be localized in cases of underlying local dermatosis such as venous stasis, postherpetic neuralgia, or brachioradial pruritus.[23]

PN is a clinical diagnosis. Patients with PN will likely have a history of chronic severe pruritus with excoriations and flesh-colored, pink nodular lesions on extensor surfaces. Dermoscopy can be a helpful tool when diagnosing PN versus HLP. In one study, dermoscopy of HLP demonstrated pearly white areas and peripheral striations, gray-blue globules, comedo-like openings, red dots and globules, brownish-black globules, and yellowish structures. In PN, red dots and globules and pearly white areas with peripheral striations were observed under dermoscopy.[24] A skin biopsy may be warranted for lesions that are bleeding, have formed ulcers, or are resistant to first-line therapies.

In patients with PN and severe pruritus, underlying causes of severe pruritus should be evaluated, including renal disease, liver disease, thyroid disease, HIV infection, malignancy, or parasitic infection.[25] Evaluation of these causes includes a complete blood cell count, complete metabolic panel, thyroid studies including thyroid-stimulating hormone and free thyroxine (T4), urinalysis, stool exam, HIV antibodies, and chest X-ray. Serum immunoglobulin E levels can also be elevated in patients with PN and atopic dermatitis.[26]

Diagnostikk

Diagnosen stilles ut fra sykehistorien og utseendet av knutene i huden. Knutene er vanligvis lokalisert på strekkesidene av armer og hender eller legger og føtter, eller på kroppen, oftest på ryggen. Knutene varierer i størrelse fra 2-3 mm og opptil 2-3 cm. Typisk er de litt rødere enn vanlig hud, men ofte med en mørk kant rundt basis av knuten. Vanligvis er knutene lokalisert symmetrisk, og det kan være fra noen få til mer enn 100 knuter.

Det er viktig å gjøre det man kan for å unngå å klø eller klore/skrape den kløende huden.

Det er vanlig å forsøke en blanding av ulike betennelsesdempende salver eller kremer på selve utslettet, og kombinere dette med medisiner i tablettform som demper kløe. Noen smertestillende medisiner kan ha effekt, og det er vist effekt av antidepressiver kan dempe følsomheten i hudnervene, og bidra til bedre søvn. Et aktuelt og lovende alternativ er å bedøve hudnervene med capsaicin (som finnes i chilipepper) som smøres på utslettene. UV-bestråling er også et aktuelt alternativ. Nye immundempende medikamenter er under utprøvning og har vist lovende effekt.

Behandlingen er komplisert, og det er oftest behov for hjelp fra hudlege.