Jump to: Page Content, Site Navigation, Site Search,
You are seeing this message because your web browser does not support basic web standards. Find out more about why this message is appearing and what you can do to make your experience on this site better.
Adrian Mindel
Infection with HIV causes a spectrum of clinical
problems beginning at the time of seroconversion (primary HIV) and
terminating with AIDS and death. It is now recognised that it may take
10 years or more for AIDS to develop after seroconversion. The Centers for Disease Control (CDC) in the USA developed the most widely used
classification for HIV disease based on the presence of clinical symptoms and signs, the presence of certain conditions and
investigative findings, the availability of HIV screening and the
degree of immunosuppression as measured by the CD4 lymphocyte count.
The infection is divided into four groups:
This article has been adapted from
the forthcoming 5th edition of ABC of AIDS. The book will be
available from the BMJ bookshop and at www.bmjbooks.com
![]()
Introduction
Summary of CDC 1992 classification system for HIV disease
Group I Primary HIV infection
Group II Asymptomatic phase
Group III Persistent generalised lymphadenopathy
Group IV Symptomatic infection
Group IV is subdivided into several subgroups and some of these (groups IVA, B, C1 and D) are AIDS defining conditions.
In 1992 the CDC included all HIV infected persons with CD4 lymphocyte counts of <200×106 cells/l as fulfilling an AIDS defining diagnosis. However, this additional classification is not widely used outside the USA.
A second classification also combines clinical and CD4 count
information. Symptoms and clinical findings are graded in severity from
A to C and CD4 counts as they fall from 1 to 3.
| |
Group I Primary HIV infection |
|---|
Primary HIV infection (PHI) is also called the seroconversion illness or acute HIV infection. It represents the stage of infection after the acquisition of the virus when antibodies are developing. Between 25% and 65% of people have been found to present with symptoms at the time of seroconversion. These can range from a mild, glandular fever-like illness to an encephalopathy. The severe symptoms are rare. The differential diagnosis of the mild seroconversion illness is protean and, without a high index of suspicion and a history indicating relevant risk behaviours or factors, the diagnosis may be missed.
|
Summary of CDC 1993 classification system for HIV disease
| ||||||||||||||||||||||||||||||
|
The appropriate diagnostic tests for PHI, which should be carried out on serial blood samples, include tests for HIV antibodies and antigen. If these are negative and PHI is suspected, the definitive test is an HIV RNA polymerase chain reaction, which is the most sensitive test for the detection and quantification of the virus. Some of these assays are not routine and the interpretation of investigation results during PHI is difficult, therefore close consultation with colleagues in virology is strongly advised.
|
Clinical manifestations of primary HIV infection
|
At the time of PHI there is sometimes a high rate of viral replication, leading to a transient rise in HIV viral load and concomitant immunosuppression due to a short lived fall in the CD4 count. This may result in manifestations of HIV disease which are normally seen later in the infection, for example oral candida. Diagnostic confusion as to the stage of HIV infection may arise, which can only be resolved by following up the patient for long enough to see the symptoms and signs resolve, HIV antibodies appear, the viral load fall and the CD4 count rise. Treatment should be directed at alleviating any symptoms, and there is considerable interest in the possible use of antiretroviral agents at this time because the virus may be more susceptible due to the relatively low numbers of virus particles which can replicate, the reduced ability of the predominantly non-syncytium inducing strains of virus to infect a wide variety of cell types and the enhanced immune response seen in PHI.
Such treatment may decrease long term damage to the immune system and delay or even prevent the development of AIDS. However, if not started within 12-18 months of PHI the theoretical advantage may be lost and, in any case, has to be balanced against the uncertain outcome, drug toxicity, adherence difficulties and the possibility of developing resistant virus, limiting future treatment options.
|
Differential diagnosis of glandular fever-like illness
| ||||||||||||||||||||||||||||||||||||||
| |
Group II Asymptomatic infection |
|---|
After PHI, HIV antibodies continue to be detectable in the
blood. The amount of virus in blood and lymphoid tissues falls to very
low levels and the rate of HIV replication is slow although it does not
cease. CD4 lymphocyte counts are within normal limits or generally
above 350×106 cells/l. This phase may persist for 10 years or more. The role of antiretroviral therapy during asymptomatic
infections is discussed in chapter 9. The decision to treat is made on
the basis of the CD4 count and the viral load. The aim of therapy is to
maintain immune function by suppressing viral replication to prevent
further damage to the immune system. As for PHI treatment, the
potential gain of therapy must be weighed against the potential risks
and uncertainties.
| |
Group III Persistent generalised lymphadenopathy |
|---|
Persistent generalised lymphadenopathy may be a presenting feature of HIV infection in a person who is otherwise well. HIV related lymphadenopathy persists for at least three months, in at least two extra-inguinal sites and is not due to any other cause.
|
Common causes of generalised lymphadenopathy
| ||||||||||||||||||||||||||||||||||||
|
Indications for lymph node biopsy
|
A lymph node biopsy in HIV disease is not recommended as a routine procedure as the findings are non-specific and the presence of lymphadenopathy due to HIV alone does not worsen the prognosis. The indications for a biopsy are the same in HIV and non-HIV related conditions.
|
Constitutional symptoms in HIV infection
|
| |
Group IV Symptomatic HIV infection before the development of AIDS |
|---|
The progression of HIV infection is a result of a decline in
immune competence that occurs due to increased replication of HIV from
sites where it has been latent. The exact triggers for this
reactivation are poorly understood. As the disease progresses, infected
persons may suffer from constitutional symptoms, skin and mouth
problems and haematological disorders, many of which are easy to treat
or alleviate. A decrease in viral load in response to the introduction
of antiretroviral therapy often corresponds to a complete or partial
resolution of these symptoms.
| |
Constitutional symptoms |
|---|
Common constitutional symptoms associated with Group IVA HIV infection include malaise, fevers, night sweats, weight loss and diarrhoea. The exact criteria for diagnosing the AIDS defining HIV wasting syndrome are the combination of 10% weight loss from baseline and one of the other serious symptoms set out in the box. Many patients find these symptoms worrying and debilitating and they should be investigated to diagnose treatable causes other than HIV. Once other causes have been excluded, symptomatic treatment can include antipyretics, antidiarrhoeal agents and if all else fails, steroids.
|
Skin and mouth problems associated with HIV
Skin problems
Mouth problems
|
| |
Skin and mouth problems |
|---|
Many skin problems occur in patients with HIV infection. These may represent exacerbations of previous skin disease, or a new problem. Identical skin conditions occur in HIV negative persons. However, in the immunocompromised, these common conditions may be more severe, persistent and difficult to treat. Many minor opportunistic infections (Group IVC2) manifest themselves on the skin and in the mouth. Seborrhoeic dermatitis is frequently seen and usually presents as a red scaly rash affecting the face, scalp and sometimes the whole body. This condition often responds well to 1% hydrocortisone and antifungal cream.
|
Other common dermatoses that respond to antifungal creams (eg, clotrimazole) include tinea cruris and pedis and candidiasis. Folliculitis often responds to 1% hydrocortisone and antifungal cream, impetigo to antibiotics and shingles to aciclovir, valaciclovir or famciclovir. Recurrent perianal or genital herpes may become more troublesome, with recurrences lasting longer and occurring more frequently; if this persists for more than 3 months it is considered an AIDS defining opportunistic infection (Group IVC1). Treatment with long term aciclovir, valaciclovir or famciclovir suppression is often required. Genital and perianal warts are common, difficult to treat and frequently recurrent, and high grade cervical dysplasia is seen more often in HIV infected women.
|
Mouth problems are also common, cause considerable distress and when
severe may result in difficulty with eating and drinking. Oral candida
can be managed with topical or systemic antifungals (eg nystatin,
ketoconazole or fluconazole). If dysphagia develops, oesophageal
candidiasis should be suspected and investigated. Oral hairy
leucoplakia can be differentiated from oral candida by its
characteristic distribution along the lateral borders of the tongue and
the fact that it cannot be scraped off. Although unsightly, this
condition which is due to Epstein-Barr virus reactivation is painless
and temporary remission can be obtained with aciclovir, valaciclovir or
famciclovir. Other oral conditions including dental abscesses, caries,
gingivitis and oral ulceration (herpetic or bacterial) may occur. Mouth
ulcers may be particularly difficult to treat and expert specialist
assessment is recommended. Metronidazole, aciclovir, 0.2%
chlorhexidine mouthwashes and analgesic sprays may all be effective
depending on the cause and, in extreme cases, thalidomide has been
used. Maintenance of good oral hygiene and dental care are important.
| |
HIV and haematological problems |
|---|
Lymphopenia with depression of the CD4 cell subset is a marker
for HIV disease. Mild to moderate neutropenia and a normochromic, normocytic anaemia of unknown origin are often seen but usually have no
adverse effect on HIV infected individuals. Severe anaemia or
neutropenia should be investigated for other underlying causes. Thrombocytopenia is common in HIV disease and, only if persistent, causing bleeding and less than 20 × 109/l warrants
treatment with antiretrovirals which is usually effective. Many
therapies used to treat HIV may be toxic to bone marrow.
| |
Risk of progression and the value of surrogate markers |
|---|
One of the hardest problems confronting the physician dealing with an asymptomatic patient with HIV infection is predicting how soon that patient will progress to symptomatic disease or AIDS. This issue is important, first, in terms of counselling and secondly, to decide which patients may benefit from antiretroviral treatment or prophylaxis to prevent opportunistic infections.
|
|
Prognostic indicators in HIV infection
|
Variables associated with rapid disease progression include a symptomatic PHI, older age at diagnosis and receiving a large inoculum of virus, for example via a contaminated transfusion from a donor with a high viral load. The effect of prophylaxis against opportunistic infections (eg, cotrimoxazole for pneumocystis and toxoplasmosis) has been to delay the onset of AIDS and to change the pattern of disease represented by the first AIDS defining illness. Antiretroviral treatment has independently been shown to increase survival before and after AIDS. Some infected individuals do not progress for many years and work is in progress to determine whether this is due to their genetic makeup, amount of viral inoculum, characteristics of the infective virus or their immune system.
Patients who may need close monitoring include individuals whose CD4
count falls below 350×106 cells/l, those with a rapidly
declining CD4 count, those with a rising viral load and patients who
are symptomatic as they may all be candidates for antiretroviral
therapy. Patients who present with persistent constitutional symptoms,
mouth or skin problems should be considered for antiretroviral therapy
irrespective of CD4 count and viral load. These issues are discussed
further in the chapters on treatment of infections and antiretroviral agents.
| |
General management of HIV infected people |
|---|
One of the most important aspects of dealing with any HIV infected person is confidentiality. Maintaining confidentiality might be complicated: for example the patient's family or friends may not know his or her diagnosis or sexual orientation; people at work (or school) may seek medical information (especially if the individual is having time off work); or the person may fear that information may inadvertently be given to third parties. Special precautions may be required, firstly to reassure the patient that confidentiality is protected and, secondly, to limit any unwarranted dissemination of confidential information.
|
General management of the HIV infected person
|
|
The routine medical management of these individuals is usually
straightforward. They should be seen regularly, for example every three
to six months. At each visit the patient's weight should be recorded
and special attention given to mouth or skin problems and, if
necessary, they should be referred to the appropriate specialist.
Screening for STDs and hepatitis viruses should be offered if the
individual is at risk and hepatitis A and B vaccines can be safely
given. Repeating a full blood count and measuring the CD4 count and
viral load every three to six months allows early detection of actual
or imminent immune dysfunction. Patients should be advised to reattend
if they develop any symptom, especially those suggestive of
opportunistic infections or cancers, for example shortness of breath,
cough, haemoptysis, pain or difficulty in swallowing, diarrhoea, weight
loss, fevers, headaches, fitting, altered consciousness or purple spots
on their skin. Other symptoms may indicate increased viral replication
and the need to consider treatment.