Discoïde Lupus - Huidziekten Begrijpen en Behandelen

Diskoider Lupus erythematodes

Normalerweise bekämpft das Immunsystem alles, was für den Körper fremd und schädlich ist und toleriert und schützt körpereigenes Gewebe. Beim diskoiden Lupus erythematodes wenden sich Antikörper gegen körpereigenes Gewebe und führen zu stark entzündlichen Reaktionen und Zelltod. Diese Form der Lupus-Erkrankung ist auf wenige Hautbereiche beschränkt und weitet sich nicht auf andere Organsysteme aus. Die genaue Entstehung ist noch nicht vollständig geklärt. Viele Faktoren wie genetische Veranlagung, Defekte in der Immunabwehr, UV-Strahlung und Medikamente spielen eine Rolle. Gewisse Rassen wie Collie, Deutscher Schäferhund, Sheltie, Siberian Husky und Deutsch Kurzhaar sind häufig betroffen. Durch Sonneneinstrahlung kommt es zu einer Verschlechterung der Erkrankung.

Abb. 2: DLE Depigmentierung, Geschwüre und Verlust des Oberflächenreliefs

Prognosis

Although the prognosis of patients with discoid lupus erythematosus (DLE) is favorable regarding mortality, morbidity can be considerable. Patients may experience pain or burning of their lesions, or occasionally pruritus. Many patients with DLE experience disfigurement from the scars or atrophy that can develop. Scarring alopecia is particularly disturbing for patients. Prompt treatment of early lesions may help prevent or lessen the severity of scarring and atrophy. Discoid lupus erythematosus is known to negatively impact patient quality of life. [14] In fact, a 2016 study demonstrated that over one third of patients with cutaneous lupus met criteria for depression or anxiety with need for psychiatric intervention. [15] Furthermore, a significant correlation has been found between skin disease activity in cutaneous lupus and quality of life. [16]

Exacerbation is common with increased sun exposure, particularly in the spring and summer. Serious systemic disease is rare, but when it occurs, patients may develop life-altering sequelae. Malignant degeneration within DLE lesions is uncommon, but may occur. Hence, prompt biopsy of suggestive lesions developing within chronic DLE lesions is warranted. [17, 18]

Ontstaan

CDLE wordt beschouwd als een auto-immuunziekte. Dit is een stoornis, waarbij het afweersysteem zich tegen het eigen lichaam keert. Het is normaal dat het lichaam antistoffen maakt om infecties van buitenaf te bestrijden. Maar bij CDLE zijn er zogenaamde ‘LE-antistoffen’ in de huid of in de bloedbaan aanwezig, die lichaamseigen weefsel aanvallen. Hierdoor ontstaan lokale ontstekingen van de huid en raakt de huid beschadigd. De oorzaak hiervan is nog niet bekend.

Naast een genetische aanleg zijn er andere factoren die CDLE kunnen doen ontstaan of verergeren. Daarbij kunnen omgevingsfactoren, bepaalde geneesmiddelen en ziekteverwekkers een rol spelen. Ook roken is mogelijk een uitlokkende factor. Deze gewoonte bemoeilijkt ook de behandeling.

Overgevoeligheid voor zonlicht speelt eveneens een belangrijke rol bij het ontstaan van de afwijkingen.

Er bestaan meerdere vormen van Lupus erythematodes (LE): bij CDLE is het immuunsysteem alleen gericht tegen de huid.

Introduction

Lupus erythematosus is an inflammatory, connective-tissue disease of generalized autoimmunity characterized by pathogenic autoantibodies and immune complexes, attributed to a loss of immune tolerance. For discoid lupus erythematosus without associated SLE (CDLE), the evidence does not show whether circulating inflammatory cells and autoantibodies are involved in the pathogenesis, but it is evident that the cutaneous inflammatory infiltrates are dominated by Th1, but not Th17, cells in contrast to systemic lupus erythematosus.[5][6]

Lupus can occur in all age groups, but DLE occurs more frequently in women in their fourth and fifth decades of life. Twenty-five percent of patients with SLE may develop typical discoid lesions at some point during their illness, and 1% to 5% of patients with discoid lupus may develop SLE.

Ethnicity is also a major risk factor for developing LE, and its effect in some populations is almost as strong as that of gender. SLE prevalence is four-fold higher in African-American women than White-race American women (4 in 1000 versus 1 in 1000). In addition, African-Americans tend to develop the disease at an earlier age and have a higher mortality rate.[7][8]

History and Physical

DLE is the most common form of chronic cutaneous erythematosus and can occur as localized form (80%) with lesions on the face, ears, and scalp or as disseminated DLE (20%) with lesions above and below the neck. The disseminated form of DLE, especially when involving the trunk, is associated with an increased risk of progression to SLE up to 28%.[16]

It is unusual for discoid lesions to present below the neck without lesions also being present above the neck. Occasionally, discoid lesions develop on mucosal surfaces, including the lips, nasal mucosa, conjunctivae, and genital mucosa.[5] Some patients with discoid lesions exhibit a photodistribution. Sun exposure seems to play a role in the development of lesions. However, patients can have discoid lesions on the sun-protected skin, and there is no clear association between sun exposure and their development.