The term “collagenosis” groups together a set of autoimmune diseases characterized by inflammatory and immunological damage to connective tissue, hyperactivity of the immune system, a predominance of women, association with antinuclear antibodies and the spread of lesions. The connective tissue being present throughout the body, all organs are liable to be affected in a more or less associated manner, hence the great diversity of symptoms that may result from collagenosis. The goal of their management is to control disease activity and reduce it to the lowest possible level.

Collagenoses, also called connectivitis or systemic diseases, group together a set of rare chronic autoimmune inflammatory diseases, resulting from abnormal collagen formation in tissues rich in intercellular matrix, namely connective tissues.

Collagen is the most abundant protein in our body. It allows our organs and our body to be stable without being too rigid, while being flexible enough. Secreted by connective tissue cells, collagen interacts with a large number of other molecules to form fibers and produce fibrous tissue with supportive and stretch-resistant properties.

Predominant in women, collagenases are capable of reaching all organs (digestive system, muscles, joints, heart, nervous system). This is why its manifestations are as numerous as the number of affected organs. The quality of life is sometimes very strongly impacted. The outcome of these diseases depends mainly on damage to vital organs.

The most well-known collagenosis is systemic lupus erythematosus (SLE). Collagenosis also includes the following diseases:

• rheumatoid arthritis;
• oculourethro-synovial syndrome (OUS);
• spondyloarthropathies (especially ankylosing spondylitis);
• Horton’s disease;
• Wegener’s granulomatose;
• rhizomelic pseudo-polyarthritis;
• scleroderma;
• mixed systemic disease or Sharp syndrome;
• la microangiopathie thrombotique ;
• periarteritis nodosa;
• the Gougerot-Sjögren syndrome;
• dermatomyositis;
• dermatopolymyositis;
• the maladie de Behçet;
• the sarcoïdose;
• histiocytosis;
• Still’s maladie;
• periodic illness;
• overload diseases and certain metabolic diseases;
• chronic liver disease;
• diseases of elastic tissue;
• congenital or acquired diseases of serum complement;
• scleroderma;
• Churg-Strauss syndrome;
• systemic vasculitis, etc.

They are still unknown. There is probably a disorder of the immune system, as evidenced in the blood of patients, the presence of abnormal antibodies, called autoantibodies or antinuclear antibodies, directed against the own constituents of the body’s cells. Certain antigens of the histocompatibility system (HLA) are found more readily during certain diseases, or in certain families more frequently affected, which suggests the promoting role of a genetic factor.

The connective tissue being present throughout the body, all organs are likely to be affected in a more or less associated way, hence the wide variety of symptoms that can result from attacks:

• articular;
• cutaneous;
• cardiac;
• pulmonary;
• hepatic;
• renal;
• central or peripheral nerve;
• vascular;
• digestive.

The evolution of collagenosis frequently takes the form of relapses frequently associated with an inflammatory syndrome and is highly variable individually. Nonspecific symptoms appear to varying degrees:

• fever (mild fever);
• abatement;
• chronic fatigue;
• decreased performance;
• difficulty concentrating;
• sensitivity to sun and light;
• alopecia;
• sensitivity to cold;
• nasal / oral / vaginal dryness;
• skin lesions ;
• weightloss ;
• joint pain ;
• pain inflammation of the muscles (myalgia) and joints (arthralgia).

Sometimes patients have no symptoms other than joint pain and fatigue. We then speak of undifferentiated connectivitis. Sometimes symptoms of different types of connective tissue diseases appear. This is called an overlap syndrome.

Due to the potential for multiple organ damage, it is important that different medical disciplines cooperate closely. The diagnosis is based on the history, that is to say the history of the sick person, and his clinical examination, looking for symptoms frequently encountered in one or more of these diseases.

As collagenases are characterized by a large amount of antinuclear antibody production, testing for these autoantibodies in the blood is an important element in establishing a diagnosis. However, the presence of these autoantibodies is not always synonymous with collagenase. Sometimes it is also necessary to take a tissue sample or biopsy. Referral to a specialist is recommended to confirm the diagnosis and start appropriate treatment.

The goal of managing collagenosis is to control disease activity and reduce it to the lowest possible level. The treatment is adapted according to the type of collagenosis diagnosed and according to the organs affected. Corticosteroids (cortisone) and analgesics are often used as the first line to stop relapses and calm painful manifestations. The addition of an immunosuppressant, by mouth or by injection, may be necessary. Management may also involve intravenous injections of immunoglobulins or plasma purification techniques (plasmapheresis) in a hospital environment. Some patients, such as those with lupus, may also benefit from antimalarial treatment.