Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
The major risk factor for
leishmaniasis is being exposed to infected sand flies. The sand flies are most
active after dusk and are more common in rural areas. Casual travelers do not
usually visit these areas at night, so infection is more common in adventure
travelers, Peace Corps workers, missionaries, soldiers, and those with
occupational activities that require them to live in rural areas. In healthy
people, the degree of immune response to leishmaniasis appears to be
genetically determined. In visceral leishmaniasis, a weak immune response is
associated with more severe disease. Factors that weaken the immune system
include malnutrition and infection with the human immunodeficiency virus (HIV).
However, in mucocutaneous leishmaniasis, the symptoms appear to be caused in
part by an overactive immune response. Interestingly, the Leishmania parasite
itself can be infected with a virus that may cause the parasite to be more
dangerous by overstimulating the inflammatory response from the human immune
system.
Leishmania may live quietly for years in the body and then begin to multiply
(reactivate) if the person's immune system becomes suppressed. Thus, people who
were born in a country with leishmaniasis and those who have had travel-related
exposure are at risk if they become immunosuppressed by conditions such as
chemotherapy, use of
steroids, or infection with HIV. Patients who have
previously had cutaneous leishmaniasis acquired in certain parts of the New
World are at risk for mucocutaneous leishmaniasis.
What are leishmaniasis symptoms and signs?
Visceral leishmaniasis (VL) may be mild or severe. Some patients are asymptomatic
and do not realize that they carry the parasite. Symptoms appear in weeks to
months after the bite of the sand fly. Less commonly, symptoms arise only years
later when a person's immune system becomes suppressed. The five classic
symptoms of more severe disease are
high levels of immune globulin in the blood
(hypergammaglobulinemia).
The skin may turn dark, causing VL to be called "kala-zar," which means "black
sickness." Some people who recover will have a persistent rash or pigment
changes in the skin. The kidney is also affected, which may lead to renal
failure. Other organs, including the bowel and the lung, may be affected.
Cutaneous leishmaniasis (CL) is known by a host of other names, including Oriental
sore. The site of the sand fly bite usually forms a raised papule that expands
and ulcerates, with a heaped up border on the edges. The disease becomes
manifest over several weeks. There may be only one lesion, or multiple lesions
may appear over time. The skin lesions take on a variety of appearances and may
resemble acne, warts, or psoriasis. They may look like large scaly, ulcerated
plaques, or form shallow ulcerated nodules. The lesions may be dry or weeping
and are not usually painful unless they are secondarily infected by bacteria.
Sores occur predominately on the extremities and face. They heal over months to
years, leaving scars that often resemble old burns. In severe cases, known as
diffuse cutaneous leishmaniasis, nodular lesions may occur widely and last for
years or even for life.
Figure 3: Picture of a crater lesion of leishmaniasis, skin. SOURCE: CDC
Figure 4: Picture of a skin ulcer due to leishmaniasis, hand of Central-American adult. SOURCE: CDC/Dr. D.S. Martin
Mucocutaneous leishmaniasis (ML) involves the nose, mouth, and larynx. It is
less common than VL and CL. Initially, the patient experiences a nodule at the
site of the sand fly bite with symptoms consistent with CL. Subsequently,
mucocutaneous involvement leads to nodules inside the nose, perforation of the
nasal septum, and enlargement of the nose or lips. If the larynx is involved, the
voice changes as well. Ulcerated lesions may lead to scarring and tissue
destruction that can be disfiguring. The disease occurs predominately in
Bolivia, Brazil, and Peru.
The word "rash" means an outbreak of red bumps on the body. The way people use this term, "a rash" can refer to many different skin conditions. The most common of these are scaly patches of skin and red, itchy bumps or patches all over the place.
There are many symptoms involved in the 1st, 2nd and 3rd trimesters of pregnancy. The first early pregnancy symptom is typically a missed period, but others include breast swelling and tenderness, nausea and sometimes vomiting, fatigue and bloating. Second trimester symptoms include backache, weight gain, itching, and possible stretch marks. Third trimester symptoms are additional weight gain, heartburn, hemorrhoids, swelling of the ankles, fingers, and face, breast tenderness, and trouble sleeping. Read more to learn about recommended procedures and tests for each stage of a healthy pregnancy.
Anemia is the condition of having less than the normal number of red blood cells or less than the normal quantity of hemoglobin in the blood. The oxygen-carrying capacity of the blood is, therefore, decreased.
Lymph nodes help the body's immune system fight infections. Causes of swollen lymph nodes (glands) may include infection (viral, bacterial, fungal, parasites). Symptoms of swollen lymph nodes vary greatly. They can sometimes be tender, painful or disfiguring. The treatment of swollen lymph nodes depends upon the cause.
HIV (human immunodeficiency virus) is the cause of AIDS (acquired immunodeficiency syndrome). HIV is a type of virus called a retrovirus, which infects humans when it comes in contact with a break in the skin or tissues such as those that line the vagina, anal area, mouth, or eyes.
Although a fever technically is any body temperature above the normal of 98.6 degrees F. (37 degrees C.), in practice a person is usually not considered to have a significant fever until the temperature is above 100.4 degrees F (38 degrees C.). Fever is part of the body's own disease-fighting arsenal: rising body temperatures apparently are capable of killing off many disease- producing organisms.
Drug addiction is a chronic disease that causes drug-seeking behavior and drug use despite negative consequences to the user and those around him. Though the initial decision to use drugs is voluntary, changes in the brain caused by repeated drug abuse can affect a person's self-control and ability to make the right decisions and increase the urge to take drugs. Drug abuse and addiction are preventable.
Scar formation is a natural part of the healing process after injury. The depth and size of the wound incision and the location of the injury impact the scar's characteristics, but your age, heredity and even sex or ethnicity will affect how your skin reacts.
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