Connective Tissue diseases

Connective Tissue diseases:
المرحلة الخامسة ا.د.محمد كاظم الحطاب المادة:الجلدية
Are groups of clinico pathological conditions involve connective tissue of most systems of the body, include mainly LE, scleroderma, systemic sclerosis, dermatomyositis, MCTD &others…

Lupus Erythematosus:
is an autoimmune disorder resulting from an interplay of genetic, environmental &hormonal elements with a heterogeneous clinical expression extending from a localized cutaneous form to a life threatening systemic form.
LE is a spectrum of diseases, in one end of spectrum: DLE is purely cutaneous LE, at the other end :SLE. In the middle of spectrum: sub acute LE, neonatal LE, complement deficiency LE& drug-induced LE .

Discoid Lupus Erythematosus(chronic DLE):
DLE is a relatively benign disorder of the skin, most frequently involving the face and characterized by various- sized ,reddish ,well-defined scaly patches which tend to heal with atrophy, scarring and pigmentary changes.

Etiology & pathogenesis: there should be genetic factors, these will cause somatic mutations in lymphoid stem cells during life, this will lead to forbidden clones of lymphocytes ,which synthesize autoantibodies. Normally ,an endogenous defense mechanism appears to be directed against the proliferating forbidden clones. Till now ,the patient is living with out any clinical or abnormal serological findings.
When these clones of lymphocytes become un forbidden, autoimmune disease appears .certain modifying factors in environment: uv light ,trauma, drugs , emotional tension & infection.
These factors interfere with immunological defense mechanism .so when some body exposed to these environmental factors ,the disease appears.
DLE is primarily a disease of adult life with the average time of onset in the fourth decade ,with a F:M ratio of about 2:1.