Infection and Immunology Flashcards
Define abscess.
- a painful collection of pus, usually caused by bacterial infection
What are the presenting signs and symptoms of skin abscesses?
- Swollen, pus-filled lump under the surface of the skin with associated fever and chills
What are the presenting signs and symptoms of internal abscesses?
- Pain in the affected area (or referred pain)
- Swinging fevers
- Malaise
What are the appropriate investigations for abscesses?
o Ultrasound - can be useful in visualising an abscess
What is the appropriate treatment for abscesses?
o Some small skin abscesses may disappear by themselves
o Incision and Drainage
o Antibiotics
What is the most common cause of candidiasis?
- candida albicans
What are the risk factors for candidiasis?
Broad-spectrum antibiotics
Immunocompromise (e.g. HIV, corticosteroids)
Central venous lines
Cushing’s disease
Diabetes mellitus
GI tract surgery
What are the presenting signs and symptoms of oral candidiasis?
o curd-like white patches in the mouth, which can be removed easily revealing an underlying red base
- aka as oral thrush
What are the presenting signs and symptoms of oesophageal candidiasis?
Dysphagia
Pain on swallowing food or fluids
Name some AIDS-defining illnesses?
Candidiasis of the esophagus, bronchi, trachea, or lungs (but NOT the mouth)
Cervical cancer, invasive
Coccidioidomycosis, disseminated or extrapulmonary
Cryptococcosis, extrapulmonary
Cryptosporidiosis, chronic intestinal (greater than one month’s duration)
Cytomegalovirus disease or CMV (other than liver, spleen, or nodes)
Cytomegalovirus retinitis (with loss of vision)
Encephalopathy, HIV related
Herpes simplex: chronic ulcer(s) (more than 1 month in duration); or bronchitis, pneumonitis, or esophagitis
Histoplasmosis, disseminated or extrapulmonary
Isosporiasis, chronic intestinal (more than 1 month in duration)
Kaposi sarcoma
Lymphoma, Burkitt’s (or equivalent term)
Lymphoma, immunoblastic (or equivalent term)
Lymphoma, primary, of brain
Mycobacterium avium complex or M kansasii, disseminated or extrapulmonary
Mycobacterium tuberculosis, any site (pulmonary or extrapulmonary)
Mycobacterium, other species or unidentified species, disseminated or extrapulmonary
Pneumocystis pneumonia (PCP)
Pneumonia, recurrent
Progressive multifocal leukoencephalopathy
Salmonella septicemia, recurrent
Toxoplasmosis of brain
Wasting syndrome due to HIV
What are the presenting signs and symptoms of candidal skin infections?
Soreness and itching
Skin appearance can be variable
Red, moist skin area with ragged, peeling edge and possibly papules and pustules
What are the appropriate investigations for candidiasis?
o depends on the site
- oral candidiasis = swabs and cultures are not particularly useful because a lot of normal people have candida in their mouth
- oesophageal candidiasis = definitive diagnosis is by endoscopy
- invasive candidiasis = blood cultures required if candidaemia is possible
o therapeutic trials of antifungal (e.g. fluconazole) can help with diagnosis
Define cellulitis?
Acute non-purulent spreading infection of the subcutaneous tissue, causing overlying skin inflammation
What are the presenting symptoms of cellulitis?
o History of cut, scratch or injury
o Symptoms dependent on the location of the cellulitis
- periorbital cellulitis - painful swollen red skin around the eye
- orbital cellulitis - painful or limited eye movements, visual impairment
What are the signs of cellulitis on examination?
o Lesion - erythema, oedema, warm tender indistinct margins, pyrexia - may suggest systemic spread
o Periorbital - swollen eye lids, conjunctival infection
o Orbital Cellulitis - proptosis, impaired visual acuity and eye movements, test for RAPD, visual acuity and colour vision
What is the treatement for cellulitis?
o Medical = oral penicillins (e.g. flucloxacillin) or tetracyclines are effective
o Surgical = orbital decompression may be needed in orbital cellulitis (EMERGENCY)
What are the possible complications of cellulitis?
Sloughing of overlying skin
Orbital cellulitis - may cause permanent loss of vision, spread to the brain, abscess formation, meningitis, cavernous sinus thrombosis
Was viruses cause herpes?
- HSV1 = oral herpes
- HSV2 = genital herpes
What are the presenting symptoms of HSV1 infection?
o Pharyngitis, Gingivostomatitis (eating might be painful), Herpetic whitlow (abscess at the end of the finger caused by infection with HSV - it is very painful)
o THEN WHEN ON REACTIVATION = Prodrome of perioral tingling and burning, Vesicles/cold sores appear, Complete healing within 8-10 days
What are the presenting symptoms of HVS2?
Painful blisters and rash in the genital, perigenital and anal area
Dysuria
Fever
Malaise
What are the presenting symptoms of HSV2 encephalitis?
Usually caused by HSV1 so causes HSV1 type symptoms
What are the presenting symptoms of HSV2 keratoconjunctivitis?
Watering eyes
Photophobia
What are the signs of HVS1 infection on examination?
Tender cervical lymphadenopathy
Erythematous, oedematous pharynx
Oral ulcers filled with yellow slough (gingivostomatitis)
Herpetic whitlow
o Herpes Labialis (reactivation affecting the mouth) - Perioral vesicles/ulcers/crusting
What are the signs of HVS2 infection on examination?
Maculopapular rash
Vesicles
Ulcers
All of these are found on the external genitalia, anal margin and upper thighs
Inguinal lymphadenopathy
Pyrexia