Tuberculosis in the Lung

Tuberculosis is caused by a group of organisms Mycobacterium tuberculosis, M. bovis, M. africanum and a few other rarer subtypes. Tuberculosis usually appears as a lung (pulmonary) infection. However, it may infect other organs in the body. Recently, antibiotic-resistant strains of tuberculosis have appeared. With increasing numbers of immunocompromised individuals with AIDS, and homeless people without medical care, tuberculosis is seen more frequently today. (Courtesy of the Centers for Disease Control.)

Kaposi's Sarcoma - Lesion on the Foot

Kaposi's sarcoma on the foot. This once-rare malignancy of the blood vessels is now associated with AIDS. It is more frequently associated with AIDS in homosexual men than AIDS in IV drug users. The malignancy results in purplish grape-like lesions in the skin, gastrointestinal tract and other organs.

AIDS

AIDS (acquired immune deficiency syndrome) is caused by HIV (human immunodeficiency virus), and is a syndrome that leaves the body vulnerable to a host of life-threatening illnesses. There is no cure for AIDS, but treatment with antiviral medication can suppress symptoms. AIDS is universally fatal, in large part due to the proliferation of opportunistic infections.

STDs and Ecological Niches

Many sexually-transmitted diseases (STDs) invade the host and reside for long periods of time without killing the host. A good example is syphilis, which may reside in its host for 30 to 50 years. HIV also can take 10 or more years to kill its host, allowing plenty of time to spread the infection.

HIV

HIV (human immunodeficiency virus) is a viral infection that gradually destroys the immune system. Practicing effective safe sex methods significantly reduces the risk of disease transmission.

Primary HIV Infection

HIV (human immunodeficiency virus) is more frequently transmitted through unprotected sex or sharing contaminated needles. Transmission from mother to fetus or through blood products has significantly declined in the United States.

Canker Sore (Aphthous Ulcer)

Canker sores (Aphthous ulcers) are very common. Typically, they are a shallow ulcer with a white or whitish/yellow base surrounded by a reddish border. This ulcer is seen in an individual with AIDS and is located in front and just below the bottom teeth.

Mycobacterium Marinum Infection on the Hand

This bacterial infection is caused by Mycobacterium marinum, and is not frequently seen (atypical). Marinum is a relative of the organism which causes tuberculosis. This lesion is often referred to as a swimming pool granuloma. Atypical mycobacterial infections may cause life-threatening disease in people with weakened immune systems (immunocompromised individuals).

Dermatitis, Seborrheic - Close-Up

This is a close-up of seborrheic dermatitis. Note the redness (erythema) and mild scaling. Individuals with AIDS frequently develop seborrheic dermatitis or other types of skin rashes, as seen in this person.

Dermatitis, Seborrheic on the Face

This is seborrheic dermatitis on the face. Note the redness (erythema) and mild scaling. Individuals with AIDS frequently develop seborrheic dermatitis or other types of skin rashes, as seen in this person who is HIV positive.

Histoplasmosis, Disseminated in HIV Patient

This is a skin lesion resulting from disseminated histoplasmosis. Histoplasmosis occurs most frequently as a lung infection, however it can infect the skin or become distributed (disseminated) to internal organs.

Molluscum on the Chest

These lesions are associated with the molluscum virus and are present on a person who has a weakened immune system (immunocompromised). Molluscum contagiosum are small, raised, pearly skin lesions caused by the molluscum virus, a member of the poxvirus family. They are seen frequently in children and less often in adults. In adults, they may be considered a sexually transmitted disease. Immunocompromised individuals may experience heavy outbreaks of these lesions, as seen in this photograph.

Kaposi's Sarcoma on the Back

Kaposi's sarcoma was once a rare malignancy of the blood vessels but is now associated with AIDS. It is more frequently associated with AIDS in homosexual men than AIDS in IV drug users. Recent research has suggested that this malignancy may be caused by a newly discovered herpes virus. The malignancy results in purplish, grape-like lesions in the skin, gastrointestinal tract, and other organs.

Kaposi's Sarcoma - Close-Up

Kaposi's sarcoma was once a rare malignancy of the blood vessels but is now associated with AIDS. It is more frequently associated with AIDS in homosexual men than AIDS in IV drug users. The malignancy results most frequently in purplish to reddish-purple flat or grape-like lesions in the skin, gastrointestinal tract, and other organs.

Kaposi's Sarcoma on the Thigh

Kaposi's sarcoma, seen here on the thigh, was once a rare malignancy of the blood vessels, but is now associated with AIDS. It is more frequently associated with AIDS in homosexual men than AIDS in IV drug users. The malignancy results in purplish to reddish-purple grape-like lesions in the skin, gastrointestinal tract, and other organs.

Kaposi's Sarcoma - Perianal

Kaposi's sarcoma usually occurs in male homosexuals with AIDS. These lesions can appear anywhere on the body as purple, elevated growths. This sarcoma is located near the anus (perianal).

Molluscum Contagiosum on the Face

Molluscum contagiosum is most commonly seen in children, however it does occur in adults and may cause extensive infection in people with weakened immune systems (immunocompromised). In this photograph, multiple small molluscum are seen covering the cheek, upper neck, and in the sideburn.

Herpes Zoster (Shingles), Disseminated

Herpes zoster (shingles) normally occurs in a limited area that follows a dermatome (see the "dermatome" picture). In individuals with damaged immune systems, herpes zoster may be widespread (disseminated), causing serious illness. Herpes zoster is caused by the same virus that causes chickenpox.

Antibodies

Antigens are large molecules (usually proteins) on the surface of cells, viruses, fungi, bacteria, and some non-living substances such as toxins, chemicals, drugs, and foreign particles. The immune system recognizes antigens and produces antibodies that destroy substances containing antigens.