Lyme Disease Essays (1204 words) - Medicine, Clinical Medicine, RTT

Lyme Disease Lyme Disease Lyme Arthritis ~~~~~~~~~~~~~~ Lyme disease is a tick-transmitted inflammatory disorder characterized by an early focal skin lesion, and subsequently a growing red area on the skin (erythema chronicum migrans or ECM). The disorder may be followed weeks later by neurological, heart or joint abnormalities. Symptomatology ~~~~~~~~~~~~~~ The first symptom of Lyme disease is a skin lesion. Known as erythema chronicum migrans, or ECM, this usually begins as a red discoloration (macule) or as an elevated round spot (papule). The skin lesion usually appears on an extremity or on the trunk, especially the thigh, buttock or the under arm. This spot expands, often with central clearing, to a diameter as large as 50 cm (c. 12 in.). Approximately 25% of patients with Lyme disease report having been bitten at that site by a tiny tick 3 to 32 days before onset of ECM. The lesion may be warm to touch. Soon after onset nearly half the patients develop multiple smaller lesions without hardened centers. ECM generally lasts for a few weeks. Other types of lesions may subsequently appear during resolution. Former skin lesions may reappear faintly, sometimes before recurrent attacks of arthritis. Lesions of the mucous membranes do not occur in Lyme disease. The most common symptoms accompanying ECM, or preceding it by a few days, may include malaise, fatigue, chills, fever, headache and stiff neck. Less commonly, backache, muscle aches (myalgias), nausea, vomiting, sore throat, swollen lymph glands, and an enlarged spleen may also be present. Most symptoms are characteristically intermittent and changing, but malaise and fatigue may linger for weeks. Arthritis is present in about half of the patients with ECM, occurring within weeks to months following onset and lasting as long as 2 years. Early in the illness, migratory inflammation of many joints (polyarthritis) without joint swelling may occur. Later, longer attacks of swelling and pain in several large joints, especially the knees, typically recur for several years. The knees commonly are much more swollen than painful; they are often hot, but rarely red. Baker's cysts (a cyst in the knee) may form and rupture. Those symptoms accompanying ECM, especially malaise, fatigue and low-grade fever, may also precede or accompany recurrent attacks of arthritis. About 10% of patients develop chronic knee involvement (i.e. unremittent for 6 months or longer). Neurological abnormalities may develop in about 15% of patients with Lyme disease within weeks to months following onset of ECM, often before arthritis occurs. These abnormalities commonly last for months, and usually resolve completely. They include: 1. lymphocytic meningitis or meningoencephalitis 2. jerky involuntary movements (chorea) 3. failure of muscle coordination due to dysfunction of the cerebellum (cerebellar ataxia) 4. cranial neuritis including Bell's palsy (a form of facial paralysis) 5. motor and sensory radiculo-neuritis (symmetric weakness, pain, strange sensations in the extremities, usually occurring first in the legs) 6. injury to single nerves causing diminished nerve response (mononeuritis multiplex) 7. inflammation of the spinal cord (myelitis). Abnormalities in the heart muscle (myocardium) occur in approximately 8% of patients with Lyme disease within weeks of ECM. They may include fluctuating degrees of atrioventricular block and, less commonly, inflammation of the heart sack and heart muscle (myopericarditis) with reduced blood volume ejected from the left ventricle and an enlarged heart (cardiomegaly). When Lyme Disease is contracted during pregnancy, the fetus may or may not be adversely affected, or may contract congenital Lyme Disease. In a study of nineteen pregnant women with Lyme Disease, fourteen had normal pregnancies and normal babies. If Lyme Disease is contracted during pregnancy, possible fetal abnormalities and premature birth can occur. Etiology ~~~~~~~~ Lyme disease is caused by a spirochete bacterium (Borrelia Burgdorferi) transmitted by a small tick called Ixodes dammini. The spirochete is probably injected into the victim's skin or bloodstream at the time of the insect bite. After an incubation period of 3 to 32 days, the organism migrates outward in the skin, is spread through the lymphatic system or is disseminated by the blood to different body organs or other skin sites. Lyme Disease was first described in 1909 in European medical journals. The first outbreak in the United States occurred in the early 1970's in Old lyme, Connecticut. An unusually high incidence of juvenile arthritis in the area led scientists to investigate and identify the disorder. In 1981, Dr. Willy Burgdorfer identified the bacterial spirochete organism (Borrelia Burgdorferi) which causes this disorder. Affected Population ~~~~~~~~~~~~~~~~~~~ Lyme Disease occurs in wooded areas with populations of mice and deer which carry ticks, and can be contracted during any season of the year. Related Disorders ~~~~~~~~~~~~~~~~~ Rheumatoid Arthritis is a disorder similar in appearance to