In terms of its size, the human immunodeficiency virus (HIV) is like a pinhead upon a pinhead, being around 1/60th the size of the white blood cells it infects. However, both its effect on infected individuals and its rapid spread throughout the world have made the virus highly visible to humankind. Furthermore, the immune suppression that HIV causes can lead to several conditions that make the HIV infection itself visible to the outside world. The majority of these are not due to HIV infection itself, but are instead a result of 'opportunistic' infection with other diseases once the individual's immune system has become compromised. This entry looks at these so-called 'stigmata' of HIV infection. Curiously, many are caused by the human herpes viruses: you'll find mentions of herpes simplex, varicella-zoster, the Epstein-Barr virus, cytomegalovirus and human herpes virus 8.

The conditions listed here may also occur in individuals who do not have HIV. In some cases, it is only the severity of the condition that suggests the possibility of HIV infection, or some other form of immune compromise. Equally, not all individuals with HIV will develop these conditions, and some are indicative of the Acquired Immune Deficiency Syndrome (AIDS), the advanced illness caused by HIV.

Oral Candida

Candida is a yeast that is normally suppressed by the immune system. Infection with candida (aka candidiasis or 'thrush') is certainly not limited to individuals with HIV – anyone taking antibiotics, suffering from diabetes or who has temporarily depressed their immune system through stress or alcohol use may develop thrush. This may occur around the mouth or milk ducts, the vagina in women, or beneath the foreskin in men.

Oral candida often consists of a whitish covering of the inner cheeks, gums or throat that can be scraped away, but may also manifest as a red, sore tongue¹. Oral candida is common in individuals with HIV, but can occur in anyone, especially individuals with asthma who use steroid inhalers. On the other hand, candida of the oesophagus (gullet) is indicative of AIDS, and is far more serious as it may cause ulceration and make swallowing painful and difficult. Individuals with AIDS may also develop candida infection of the skin or lungs. Treatment in all cases is with anti-fungal agents such as nystatin.

Oral Hairy Leukoplakia

Oral hairy leukoplakia is a benign condition that occurs most commonly in individuals with HIV, though it may also affect those with other forms of immune compromise. It is caused by an infection of the B lymphocytes² in the throat with the Epstein-Barr virus (EBV)³. Normally, such an infection would be regulated; however, the immune suppression caused by HIV infection allows the virus to infect the tongue, creating a 'hairy' or 'feathery' white plaque on one or both side edges. These plaques can also appear on the gums, inner cheeks and flat surfaces of the tongue, but unlike candida, cannot be scraped away. Oral hairy leukoplakia is often painless, and can vary in appearance on a daily basis. No specific treatment is required, though the antiviral acyclovir may be used to treat the infection.

Facial Molluscum Contagiosum

Despite its confusing name, molluscum contagiosum is caused by a pox virus that is spread both sexually and by other forms of skin-to-skin contact. It causes smooth, skin-coloured lumps just a few millimetres in size⁴, which can spread across the skin if the lesions are picked at or scratched. While molluscum can occur in any individual, those with HIV and other conditions causing immune compromise are liable to develop large areas of molluscum infection on their faces. Whereas lesions in individuals with a normal immune system are easily treated in a similar manner to warts, facial molluscum in individuals with HIV can prove more difficult to clear.

CMV Retinitis

Individuals with HIV and other forms of immune compromise are liable to infection of multiple organs with cytomegalovirus (CMV). CMV infection of the eye commonly leads to CMV retinitis⁵, which if left untreated will cause visual loss and quickly lead to blindness. CMV retinitis is not visible on plain inspection of the eye, but is included here as it can be seen by a doctor using an ophthalmoscope⁶, and has a classical red and yellow 'pizza' appearance. Treatment of CMV retinitis is with the antiviral gancyclovir and, if necessary, surgery to repair retinal detachment or to instil the antiviral inside the eye.

Seborrhoeic Dermatitis

Seborrhoeic dermatitis is a common, benign condition that causes dry, flaky skin on the scalp, around the eyebrows, nostrils and mouth, and in severe cases on the chest, armpits, and around the pubic region. While the condition mildly affects a small percentage of the population at large, moderate-to-severe seborrhoeic dermatitis occurs in a large number of individuals with advanced HIV infection. As the condition is thought to be associated with fungal infection of the skin, treatment is with anti-fungal shampoos and creams, along with a steroid cream to reduce the inflammation of the skin.

Disseminated Zoster

The varicella-zoster virus (VZV) is responsible for two well-known diseases: chickenpox and shingles. The first time an individual is infected with VZV, they will develop chickenpox, aka varicella, an unpleasant condition marked by a rash of infectious pocks. Once this has happened, the individual is immune to chickenpox and will not have the disease again; however, if their immune system is depressed later in their life, they may develop shingles, aka zoster. As VZV spends its time between illnesses hidden in the nervous system, an episode of zoster consists of a pox rash that spreads along the route of a single nerve.

Anyone who has previously been infected with VZV can suffer from a case of zoster along a single nerve, be it across part of one side of the face, or on a line around one side of the torso. However, individuals with HIV are liable to develop disseminated zoster, in which several nerves are affected at once and multiple pox rashes appear. As for its relative EBV (see above), treatment of VZV is with the antiviral acyclovir.

Atypical Genital Herpes

Genital herpes is a common disease caused by infection with herpes simplex virus 1 or 2, and is transmitted by sexual contact. In the general population, some individuals carry the virus without symptoms. However, others develop painful fluid-filled lesions in the genital area that become painful ulcers before eventually crusting over. These are treated with an antiviral such as acyclovir. The lesions will recur a few times each year, but the individual will spend most of the time free of ulcers, despite still being infective during these symptom-free periods.

In HIV, a different, 'atypical' form of genital herpes occurs. In this case, the lesions and ulcers persist and can be accompanied by large sores, nodules around the anus, and swelling of the lymph nodes⁷ in the groin.

Kaposi's Sarcoma

Kaposi's sarcoma is a tumour of the lining of blood and lymph vessels, and is triggered by infection with human herpes virus 8 (HHV-8). The tumour has a 'bruised' purple appearance and, though it commonly appears on the skin, may affect many parts of the body including the mouth, airways and gut. As the tumour is due to a viral infection, it commonly appears in multiple places at the same time. Kaposi's sarcoma in any individual below the age of sixty years is indicative of AIDS. While no cure exists, effective treatment of the underlying HIV has been shown to suppress further growth of Kaposi's sarcoma, though the tumour may begin to grow again after years of treatment.

Persistent Generalised Lymphadenopathy

Persistent generalised lymphadenopathy (PGL) is a swelling of the lymph nodes caused by various diseases that affect the immune system. These diseases include autoimmune conditions such as rheumatoid arthritis and systemic lupus, cancers such as non-Hodgkin lymphoma, and HIV. PGL is generalised in that multiple lymph nodes are affected, and persistent in that the swelling lasts for some time. PGL itself is harmless and does not usually indicate serious disease if found in isolation, but may alert doctors to the need to test for an underlying condition.

Unexplained Weight Loss

Though weight loss may also be due to cancer, tuberculosis and other conditions, HIV is an important cause of unexplained weight loss. HIV can produce a wasting syndrome in which the individual suffers from diarrhoea and malabsorption, leading the loss of around 10% of their weight. In other cases, the opportunistic infections associated with HIV can lead to a lesser reduction in weight. HIV medication may result in lipodystrophy, leading to a reduction of fat padding in the cheeks, but this is a separate matter.