Causes and Symptoms of Lupus
Causes of lupus
Various factors have an influence on the development of lupus. Studies suggest that genetics play an important role, but is not an absolute determining factor.
There are several genes that lead to an individual to having a predisposition for the disease, but does not necessarily have to develop it. There are other factors that influence and contribute to the onset of this disease, such as hormonal or environmental factors. For example, oestrogens, infections, emotional and physical stress, pregnancy, various drugs, and the ultraviolet light of solar radiation can trigger the activity of the disease and the start of the signs and symptoms.
Symptoms of lupus
The symptoms of lupus vary depending on the individual and the form in which they present. It can affect practically any organ, for this reason it is said that it is systemic, and the symptoms may appear and disappear. When they appear they are called flare-ups. These flare-ups, different in each patient, can be severe or mild in intensity and duration and are combined with periods of remission, during which the patient is asymptomatic.
The symptoms of the disease arise from its inflammatory basis as well as the complications caused by the specific involvement of the different organs and systems. During a flare-up of the active disease, the most common discomforts are symptoms similar to the flu (fever, fatigue, loss of weight, headaches and muscle and joint pains).
Muscular and skeletal signs and symptoms. As much as 95% of the patients mention joint pain without signs of inflammation, which makes this the most common symptom of this disease. Joint involvement is usually symmetric and often affects the small joints. These symptoms last for between 12 and 48 hours, although, sometimes, they are prolonged for up to 7 or 10 days, and they resolve without leaving sequelae.
The joint disease of lupus differs from rheumatoid arthritis in one important aspect: in lupus it is very rare that the joints are damaged. The appearance of muscle weakness is relatively common, as is muscle pain and muscle inflammation.
Skin manifestations. When the lupus affects the skin, it is known as cutaneous lupus erythematosus (CLE). Occasionally, CLE is the initial expression of the systemic disease. The lesions may be localised (only on one area of the skin) or generalised (over almost all the body).
Fever. It is one of the most common manifestations. There is no characteristic pattern and may be as night sweats and moderate, remitting and, sometimes, elevated and including shivering.
Types of cutaneous lupus erythematosus (CLE)
Acute cutaneous lupus erythematosus (ACLE). Is characterised by a reddish rash (erythema) and swelling (oedema) in the cheeks area, and is called a “butterfly rash”. These patients also have an excessive sensitivity to the sun (photosensitivity), and almost 100% are associated with systemic lupus erythematosus (SLE).
Sub-acute cutaneous lupus erythematosus (SCLE). Is a rash of reddish (erythematous), scaly (flaky) lesions in the form of a ring (annular), although, sometimes they can be lesions very similar to other diseases of the skin, such as psoriasis or eczema. They usually appear on the chest, arms and the upper part of the back. When the lesions are cured, they do not leave and scars or signs. These lesions are also very often triggered by the sun and, in some cases, by some medications. In these patients, up to 50% may start to develop a systemic lupus erythematosus (SLE).
Chronic cutaneous lupus erythematosus (CCLE). It is the most common form of cutaneous lupus erythematosus (CLE). Four out every 5 patients with CLE have a CCLE. The majority of patients never have a systemic disease, and it is estimated that only 10-20% of these patients develop a systemic lupus erythematosus (SLE). There are different clinical forms of CCLE:
- Discoid. It is the most common form. The lesions are red (erythematous) and scaly (flaky) plaques that resemble those of psoriasis. It is very typical that the lesions eventually cause scars, hair loss (alopecia) and deterioration of the skin of the area. The scars and areas of alopecia are usually for the rest of the life. They are lesions that, in the majority of patients, appear on the face, ears, nose, and scalp. On rare occasions the lesions may appear on the trunk, the arms and the hands.
- Hypertrophic. It is a particular variant form of Discoid CLE. The lesions become very thick, and very flaky on the surface and there may be warts or skin tumours.
- Mucosal. The lesions of CLE may appear in the mouth in the form of reddish (erythematous) plaques that ulcerate.
- Lupus panniculitis. It is a form in which the subcutaneous cell tissue (fatty or hypodermis) is inflamed. The lesions are painful lumps (nodules) that can ulcerate. When they are cured, they leave deep (pitted) scars due to atrophy of the fatty tissue. The areas most affected are the arms and thighs, but they also affect the buttocks, the face, the scalp and the breasts in women.
- Lupus perniosis. They are lesions that appear with the cold, and look like chilblains. In reality they are a skin manifestation of lupus. They are reddish (erythematous) plaques that appear on the fingers and palms of the hands and toes and soles of the feet. They may leave scars on being cured, and occasionally also lead to changes in the nails.
Intermittent cutaneous lupus erythematosus (ICLE). Also called “lupus tumidus”. They are reddish (erythematous) plaques somewhat swollen (oedematous) that particularly appear on the face, neck, and the upper part of the chest and back. The lesions are often triggered by the sun. They are cured without leaving signs or scars. It is very rare that these patients will have systemic lupus erythematous (SLE).
In many patients with lupus, of which the large majority have SLE, it is relatively common to observe some non-specific skin lesions, for which a diagnosis is unable to be made. Among these lesions are:
- Diffuse hair loss (it is a phenomenon that is called telogen effluvium).
- Chronic urticaria (hives).
- Urticaria with purpura (urticarial vasculitis).
- Raynaud's phenomenon. In situations of cold, the fingers and toes turn completely white, then they turn a blue colour and, finally, a red colour.
- Alopecia areata. Plaques of hair loss appear on the scalp, which later recover.
- Mucinosis. Lesions in the form of papules and nodules that can appear on the face, trunk and extremities.
- Cutaneous vasculitis. Inflammation of the small vessels of the skin.
- Livedo reticularis. Changes in skin colouring from a red - bluish colour and in the form of a net on the lower limbs and buttocks.
Heart and lung manifestations. When lupus inflames these organs , it affects, in particular, the membrane linings of the heart (the pericardium) and the lungs (the pleura), which leads to pericarditis (40% of patients) and pleuritis. The two conditions have similar symptoms: Pain in the chest and, sometimes, fever. In general, they do not usually cause any significant problem and respond well to simple medical treatment. On other occasions, the lungs or heart valves, or any of the cardiac structures may be affected. This may lead to respiratory or heart failure. Although these problems are serious, they are usually very rare in individuals with lupus and easily respond to treatment.
Renal manifestations. The kidney lesion caused by lupus is called lupus nephritis. Lupus nephritis causes inflammation and, subsequently, scarring of the small blood vessels that filter body waste in the kidney (glomerulae), which can affect its function. The majority of patients have a favourable outcome in the long-term, but it is likely that they may need to take medications for many years, and even the patients that have few flare-ups or symptoms must undergo regular check-ups indefinitely.
Signs and symptoms of lupus nephritis
Lupus nephritis can cause various signs and symptoms and the form of presentation of the disease varies widely from one individual to another. The signs of lupus nephritis include:
- Blood in the urine (haematuria). The inflammation may lead to leaks in the small blood vessels that filter body wastes in the kidney (glomerulae) and are eliminated in the urine. For this reason, the urine can be a clear pink or brown colour, although these changes are not visible on many occasions.
- Protein in the urine (proteinuria). The glomerular disease can lead to protein being eliminated in the urine. The urine may be frothy due to the loss of protein, but again this disorder may be asymptomatic in the initial phases of the disease.
- Oedema. Excess of fluid that the kidneys are unable to remove quickly and that causes swelling in the legs, ankles or around the eyes.
- Weight increase. Due to the excess fluid accumulated in the body.
- Elevated blood pressure. Due to the change in kidney function.
Neuropsychiatric manifestations. It is practically impossible to know with certainty the frequency that lupus affects the brain. This is because headaches, depression, or situations of mild hyperactivity, are very common in the general population and may be due to a mild brain inflammation due to the lupus or to many other circumstances. Furthermore, it is also possible that a depression may be “reactive” to the same disease. The patient is not depressed due to the lupus inflammation, but the fact of having lupus causes anxiety and depressive symptoms. In much more rare situations, there may be other symptoms such as behavioural changes, epilepsy, etc., which have to be appropriately treated.
Gastrointestinal and liver manifestations. Little is known about the gastrointestinal manifestations of lupus, mainly due its low frequency, although this does not mean they are unimportant. The presence of mouth ulcers is a common sign in lupus and is one of the criteria that classify this disease. The gastrointestinal symptoms may include nausea, vomiting, difficulty in swallowing, abdominal reflux and pain. In patients with lupus, an increase in the size of the liver (hepatomegaly) is common (30-50%), as well as changes in the liver enzymes (30-60%).
Haematological manifestations. Haemolytic anaemia (destruction of the red cells), leukopenia, lymphopenia, and thrombocytopenia, that is to say, a decrease in the number of red cells, lymphocytes and platelets are classification criteria of lupus. Manifestations such as autoimmune haemolytic anaemia and thrombocytopenia are common and, sometimes, can precede the rest of the manifestations of lupus by several years.
Eye manifestations. Lupus can affect any structure of the eye, of which retinal vascular manifestations are the most common. In the majority of occasions, they do not lead to loss of visual acuity. Retinal occlusive disease is a serious complication that can cause temporary or permanent blindness. The appearance of conjunctivitis in periods of clinical activity has also been reported. Dry eye is common and is due, on many occasions, to the co-existence with Sjögren syndrome.