Flashcards in GUM - Presenting problems in HIV infection Deck (22):
What can lymphadenopathy in a HIV patient represent?
Lymphadenopathy in HIV can be due to malignancy (e.g. Kaposi's sarcoma or lymphoma) or infections, especially TB. Enlarging lymph nodes should undergo investigation by FNA for mycobacterial culture and cytology for lymphoma.
What should be excluded before a diagnosis of HIV wasting syndrome is made?
The HIV wasting syndrome is an AIDS defining condition comprising 10% weight loss and either chronic diarrhoea or chronic weakness with unexplained fever. Infections, painful oral ulcers and depression should be excluded first.
How should fever in a HIV patient be investigated?
Fever is a very common presentation in HIV. Non-Salmonella bacteraemia can present with a fever without diarrhoea. PUO in HIV should be investigated with urine analysis, CXR, blood cultures and abdominal CT, which may reveal lymphadenopathy or splenic microabscesses. Bone marrow should be sampled if there are cytopaenias. TB or disseminated Mycobacterium avium infection (MIA) are common underlying causes of fever.
What is Kaposi's sarcoma
This is a lympho-endothelial tumour due to sexually transmitted herpesvirus 8. Predominantly affects men and presents with red-purple papular or nodular skin lesions. May spread to lymph nodes, lungs and the GIT. Chemotherapy is reserved for those who fail to improve on ART.
What is bacillary angiomatosis
This is a bacterial infection caused by Bartonella henselae. It causes red-purple skin lesions. May become disseminated with fevers, lymphadenopathy and hepatosplenomegaly.
What is oral hairy leucoplakia?
These are corrugated white plaques running vertically on the side of the tongue; virtually pathognomonic of HIV. It is usually asymptomatic and is due to EBV.
Name some mucocutaneous conditions associated with HIV?
Other than Kaposi's sarcoma, bacillary angiomatosis and hairy leukoplakia there are:
- psoriasis and drug reactions
- seborrhoeic dermatitis
- herpes simplex (ulcers lasting >4wks are AIDS defining)
- oral candida
What are the causes of large and small bowel diarrhoea in HIV patients? What other GIT disease can occur in HIV?
Large bowel diarrhoea: Usually caused by Campylobacter, Shigella or Salmonella. CMV colitis may occur in those with a CD4 count of <100
Small bowel diarrhoea: Presents with watery diarrhoea and wasting without fever and may be due to HIV enteropathy or have an infective causes - typically, cryptospiridiosis, microspiridiosis or disseminated MAI
Oesophageal candidasis (due to C.albicans) causes odynophagia and dysphagia. Co-existing oral candidiasis is usual. Systemic fluconazole is usually curative.
How can viral hepatitis complicate HIV infection?
HIV has shared risk factors with hepatitis B and C, so co-infection is common, particularly in IVDU and patients with haemophilia. In both HBV and HCV, HIV increases viraemia and also the risk of hepatic fibrosis and hepatoma. During treatment, a flare of hepatitis may be seen with immune recovery.
Hep B: treatment with anti-HBV drugs is indicated in all those with active HBV replication, hepatitis or fibrosis. The HAART drugs tenofovir, lamivudine and emtricitabine are useful for this.
Hep C: treatment for HCV should be deferred until ART has restored the CD4 count to >350. Response to anti-HCV therapy is similar to that in HV negative patients, but toxicity is more common.
What is HIV cholangiopathy?
A sclerosing cholangitis is seen in patients with severe immune suppression. Co-infection with CMV, and cryptosporidium may present. ERCP with cautery may be needed, and ART may also improve the condition.
What are the clinical features of PCP?
Exercise induced oxygen desaturation
Hypoxaemia on ABG
Impaired carbon monoxide transfer
Raised LDH (from lung damage)
Auscultation is unremarkable and the CXR may be normal in early disease (15-20%) but classically shows perihilar ground glass changes. Induced sputum is a sensitive diagnostic test. Co-trimoxazole is used for treatment and prophylaxis.
How does the level of immunosuppression change the clinical presentation of TB in patients with HIV?
The clinical presentation of TB depends on immune function. When the CD4 count is >200 disease is more likely to be reactivated, upper lobe, open cavitatory disease. As immunosuppression increases, the clinical pattern changes:
- disease progresses more rapidly
- X ray appearance become atypical with lymphadenopathy or effusions rather than apical cavitation
- sputum smears are often negative in the absence of cavitation
- many patients have disseminated disease with miliary pulmonary shadowing, pleural or lymph node disease or extra pulmonary TB. TB in HIV response well to short course therapy.
How can HIV cause cognitive impairment?
HIV invades the nervous system early and meningo-encephalitis may occur at seroconversion. Neuropsychiatric tests may reveal cognitive disorders ranging from asymptomatic impairment to dementia. Dementia is associated with cerebral atrophy on CT/MRI but usually responds to HAART. Progressive multifocal leucoencephalopathy (PMFL) is a fatal demyelinating condition caused by the JC virus, it presents with stroke like episodes and cognitive impairment. Vision is often affected. The presence of JC-DNA on CSF is diagnostic. No specific treatment exists and the prognosis is poor. CMV encephalitis may also cause cognitive impairment, and responds poorly to treatment.
What space occupying lesions are associated with HIV?
1) Toxoplasma infection MCC. Cerebral toxoplasmosis is caused by reactivation of residual Toxoplasma gondii cysts from past infection. Imaging reveals multiple ring enhancing space occupying lesions with surrounding oedema. Diagnosis is by imaging and serology. Treatment is with sulfadiazine and pyrimethamine, although co-trimoxazole may also be effective, with improvement in 1-2 weeks and shrinkage of lesions in 2-4 weeks.
2) Primary CNS lymphomas. High grade B cell lymphoma associated with EBV infection. Imaging typically shows a single enhancing periventricular lesion with surrounding oedema. If lumbar puncture can be safely performed, EBV-DNA can be demonstrated by PCR. Treatment is usually palliative with dexamethasone and symptom relief. Prognosis is poor.
3) Tuberculoma is identified by lesions resembling toxoplasmosis on imaging. CSF shows features of tuberculous meningitis
How can HIV increase the risk of stroke?
Atherosclerosis is enhanced by HIV and some anti-retroviral drugs. HIV can also cause vasculitis. The result is an increased incidence of stroke in patients with HIV.
What is the most common cause of meningitis in HIV patients?
Cryptococcus neoformans is the most common cause of meningitis in HIV patients. It presents subacutely with a 2-3 week history of headache, fever, vomiting and mild confusion; neck stiffness is often absent (<50%). Protein, cell counts, and glucose may be normal in the CSF, although CSF cryptococcal antigen tests have sensitivity and specificity close to 100%. Treatment is 2wks of amphotericin B followed by fluconazole. Tuberculous meningitis is also common and presents in a similar way to that in patients without HIV.
What causes myelopathy and radiculopathy in HIV?
Myelopathy most commonly results from tuberculous spondylitis. Vacuolar myelopathy causes paraparesis in advanced HIV disease. CMV polyradiculitis causes painful legs, flaccid paraparesis, saddle anaesthesia and sphincter dysfunction. Despite ganciclovir treatment functional recovery is poor.
What causes HIV retinitis?
CMV retinitis causes painless, progressive visual loss in patients with severe immunosuppression. Haemorrhages and exudates are seen on the retina. Treatment with ganciclovir or valganciclovir may halt progression but does not restore vision. The eyes may also be affected by toxoplasmosis or varicella zoster infection. Also, immune recovery with HAART sometimes causes uveitis.
What rheumatological problems are associated with HIV?
HIV can cause seronegative arthritis resembling the rheumatoid type or it can exacerbate reactive arthritis. Diffuse infiltrative lymphocytosis syndrome is a benign lymphocytic tissue infiltration that commonly presents as bilateral parotid swelling and lymphadenopathy. Hepatitis, arthritis, and polymyositis occur. Treatment is with steroids and HAART but the response is variable.
What haematological problems can present in HIV?
Normochromic normocytic anaemia and thrombocytopenia are common in advanced HIV. Antiretroviral drugs may cause haematological disorders - e.g. zidovudine causes macrocytic anaemia and neutropenia. Immune thrombocytopenia in HIV responds to steroids or immunoglobulins, together with HAART.
What renal diseases are common in HIV patients?
HIV nephropathy is an important cause of renal failure and presents with nephrotic syndrome. Outcomes of renal transplantation on HAART are good.