Definition.

Sjogrens disease is a disorder of glandular tissue of the body with resulting dryness of the eyes, mouth and other mucosal tissues. It is associated with lymphatic cell infiltration of the glands and developement of antibodies as part of an autoimmune process.

Aetiology.

The cause is primarily autoimmune where the body reacts to it's own tissue, promoted by genetic and environmental factors.In the presence of an already established autoimmune disease, the process is called Secondary Sjogrens syndrome, but if there is no such process, than the condition is called Primary Sjogrens syndrome. Autoimmune diseases that may be associated with Sjogrens include Rheumatoid Arthritis, Lupus or systemic sclerosis, amongst others.

Epidemiology.

The disease was first described in the 19th century by Mikulicz, hadden and Leber, but was subsequently associated as part of a more general disease with dry eye, and mouth, as well as glandular enlargement and arthritis. A Swedish Ophthalmologist named Sjogren, recognized and described the pattern of dry eye and other features of eye involvement with the systemic disease.

The disease is seen more in females, in the 30's-40's, but can occur in children as well. Secondary sjogrens is seen in 25% of rheumatoid patients. It is also common in scleroderma and lupus. In primary Sjogrens, with no other autoimmune disease, the syndrome is seen in 2% of the general population, especially with increasing age.

Clinical

The patient usually complains of a slowly progressive dryness of the eyes, with a feeling of grittiness - especially in the morning on waking. Tear production is reduced. The eyes then develop a secondary inflammation of the conjunctiva and cornea, with poor healing and erosion of the superficial layers of the eye. Red eye results, followed by corneal oedema, and then a blurring of vision, aggravated by the progression to ulcers in the corneal surface. The dry eye itself is termed xerophthalmia, whilst the changes to the eyeball is called keratoconjunctivitis sicca. The lacrimal glands may be enlarged.

The dry mouth is called xerostomia.This is characterised by difficulty in eating and especially swallowing dry food such as biscuits, without drinking water. The saliva provides a mechanism to maintain dental hygiene and lack results in caries, and oral infections including thrush and dental and salivary duct infection and salivary duct stones. The salivary glands including parotid and submandibular glands may enlarge.

Dryness can occur at other mucosal sites - including the trachea, bronchi and the genital tissue - especially vagina. Skin dryness can also be observed.

Systemic manifestations include stiffness, fatigue, malaise, low grade fevers,and generalized as  well as local body pain. Pain may be arthralgia as well as myalgia, but a frank arthritis may occur. The arthritis tends to be non erosive, unless as part of a frank co-occurence with Rheumatoid arthritis.

Involvement of organs can occur - including:

• Kidney
• Lungs
• Blood vessels - Raynauds and vasculitis
• Muscle
• Nerve
• Thyroid
• Secondary lymphatic malignancy

Renal involvement is characterised by tubular acidosis, with secondary kidney stones and renal impairment. The direct inflammation of the filtering mechanism of the kidney - the glomerulus is occasionally involved.

The lungs are involved as a secondary problem from reduced airway protection, and bronchitis and pneumonia may occur, as well as a infiltration and fibrosis of the lung tissue - interstitial lung disease.

Blood vessel involvement includes, spasm with cold exposure - raynauds, and more rarely, inflamation of the wall of small and medium sized blood vessels, causing obstruction and reduction of blood supply, ischaemia, and may result in peripheral nerve dysfunction, and  central brain disorder, including paralysis, dementia or meningitis / encephalitis.

Neurological problems, include cranial nerve lesions, ie trigeminal or ophthalmic nerve, and lesions of peripheral nerve - including neuropathy of sensory and motor nerves, and mononeuritis.