Other cases - general Flashcards
Differences between open angle and closed angle glaucoma
Open angle Bilateral Initially asymptomatic Mild non specific symptoms Progressive visual loss
Closed angle Unilateral Sudden onset Severely painful N+V, cloudy cornea, headache, dilated pupil Reduced visual acuity
Differences between anterior uveitis and posterior uveitis
Anterior uveitis Unilateral Autoimmune conditions Painful, ocular hyperaemia Blurry vision Increased lacrimation + photophobia
Posterior uveitis Bilateral infective Painless Blurry vision Floaters + scotomata
Define conjuctivitis
Inflammation of the lining of the eyelids and eyeball caused by bacteria, viruses, allergic or immunological reactions, mechanical/irritative/toxic or medicines
Differences between bacterial and viral conjunctivitis
Bacterial conjunctivitis Unilateral Purulent discharge Reduced vision might have a Hx of STD Urethritis/vaginal discharge?
Viral conjunctivitis Bilateral Clear discharge Normal vision Signs of viral infection e.g. URT infection
Differences between acute angle glaucoma + acute anterior uveitis + conjunctivitis
Acute angle glaucoma • Extremely painful • Decreased VA • Photophobia • Systemically unwell – acute systemic malaise • Semi-dilated or oval pupil • Hazy cornea • Halos around eyes • increased IOP
Acute anterior uveitis • Painful • VA may be reduced • Photophobia • Constricted or irregular pupils • Cloudy aqueous humour (presence of inflammatory cells in aqueous humour) [hypopyon, flare, keratic precipitates] • decreased IOP
Conjunctivitis
• Not painful
• No photophobia
• VA normal
What is rheumatc fever?
autoimmune disease that may occur 1-5 weeks after a group A β-haemolytic streptococci throat infection (URTI, may present as a sore throat)
Peak incidence – 5-15 y/o
All manifestations (joints, chorea, erythema marginatum, SC nodules) of acute rheumatic fever resolve without sequale but carditis can lead to chronic rheumatic heart disease
Which are the 4 stages of the HIV infection?
Seroconversion illness • 1-6 weeks after infection • Infectious mononucleosis – like illness – fever, night sweats, malaise, myalgia, pharyngitis, headaches, diarrhoea, neuralgia neuropathy, lymphadenopathy, maculopapular rash • Antibody tests are negative • Viral p24 + HIV RNA are elevated
Asymptomatic infection
• 18 months to 15 years
• Persistent generalised lymphadenopathy - Nodes >1cm at 2 extra-inguinal sites persisting >3 months not due to any other cause
• Progressive minor symptoms – rash, oral thrush, weight loss, malaise
• CD4 + CD8 lymphocyte levels are normal (>500 cells/mm3)
• Virus levels are low but replication continues slowly
Symptomatic infection
• Nonspecific constitutional symptoms develop – fever, night sweats, diarrhoea, weight loss
• Minor opportunistic infections – candida, oral hairy leucoplakia, herpes zoster, recurrent herpes simplex, seborrheic dermatitis, tinea infections
• This collection of symptoms + signs is referred to as AIDS-related complex (ARC) + is regarded as a prodrome to AIDS
AIDS
• CD4 count <200 cells/microlitre
• Severe immunodeficiency
• Evidence of life-threatening infections + unusual tumours
• AIDS defining conditions start to occur
o Recurrent bacterial pneumonia
o Pneumocystis pneumonia
o Fungal infections (candidiasis of oesophagus)
o Kaposi sarcoma – HHV8
o Primary lymphoma of the brain
Most common causes of viral tonsilitis
rhinovirus, coronavirus, adenovirus
A 47-year-old HIV positive patient presents with weakness of his right leg, headaches, fever and confusion that have been getting worse for the last week. CT head shows multiple ring-enhancing lesions.
Causative organism
Toxoplasma gonidii
Associated with cats
In immunocompromised - myocarditis, encephalitis, focal CNS signs, stroke, seizures
Tests - ↑IgM in acute infection, ↑IgG and toxoplasma antigen titres in acute (not useful), lymph node/CNS biopsy
CT – characteristic multiple ring-shaped contrast enhancing lesions
• HIV, neuro symptoms, multiple brain lesions with ring enhancement – toxoplasmosis
Commonest virus causing common cold
Rhinovirus
Human herpesviruse and the conditions they cause
HHV1 HHV2 HHV3 HHV4 HHV5 HHV8
HHV1 - HSV1
Respiratory, saliva
Gingivostomatitis, keratoconjuctivits, herpes labialis, Temporal lobe encephalitis
HHV2 - HSV2
Sexual contact, perinatal
Genital herpes, Neonatal herpes
HHV3 - VZV
Respiratory
Chicken pox, shingles
HHV4 - EBV
Saliva - kissing disease
Mononucleosis (associated with lymphomas, nasopharyngeal carcinoma)
HHV5 - CMV
congenital, sexual, saliva
Mononucleosis in immunocompromised
HHV8 - HHV8
Sexual contact
Causes kaposi sarcoma in immunocompromised patients
Complications of infectious mononucleosis
• Nasopharyngeal carcinoma • Hodgkin’s lymphoma • Non-Hodgkin’s lymphoma o Burkitt’s lymphoma o Primary central nervous system lymphoma
- Extreme tonsillar enlargement – upper airway obstruction
- Splenic rupture
- Haemolytic anaemia, thrombocytopenia
Define anaphylaxis
Rapidly developing airway +/or breathing +/or circulation problems usually associated with skin + mucosal changes
Acute onset
Most involve IgE
>2 organ systems are affected [most often skin + resp system]
Although skin + mucosal changes can be dramatic + uncomfortable, without ABC problems isolated skin changes do not indicate anaphylaxis
Aspirin overdose
Normal tablets?
Overdose?
Severe/fatal toxicity?
Usually 300 mg tablets
> 150mg/kg body weight/ >6.5g – overdose
> 500mg/kg body weight – severe/fatal toxicity
Paracetamol overdose
Normal tablets?
Overdose?
Severe/fatal toxicity?
Usually 500mg tablets
Recommended dose of paracetamol – 4g or 75mg/kg in 24h for an adult patient
Single acute overdose – ingestion of >4g or >75 mg/kg in a period <1h
Staggered overdose – ingestion of multiple doses of paracetamol over a period of >1h exceeding recommended dosage
Paracetamol can cause serious fatal effects at around 150mg/kg for many adults
Pathophysiology of paracetamol overdose + treatment
Overdose - liver can’t metabolise it - paracetamol metabolised via an alternative pathway by CYP450 - toxic metabolite produced (N-acetyl-p-benzoquinone imine (NAPQI) - inactivated by glutathione to prevent harm
Depleted glutathione stores - NAPQI accumulates, reacts with cells leading to necrosis
Necrosis occurs in the liver + kidney tubules
IV acetylcysteine
Indication for platelet transfusion
Active bleeding + platelets <50*109/L
or bone marrow failure + platelets <10*109/L
(normal platelet count 150-450*109/L)
What is Actinic keratosis + Bowen’s disease?
• Actinic keratosis – precancerous lesion that can turn into squamous cell carcinoma
• Bowen’s disease/squamous cell carcinoma in situ - early stage of the squamous cell carcinoma
o Tumour can be found in the epidermis but it hasn’t broken through the basement membrane
o Atypical, large, over-pigmented cells
4 subtypes of BCC
- Nodular [most common]
- Superficial [flat shape]
- Morpheic [yellow waxy plaque, scar like]
- Pigemented [dense colour, specks of colour]
https://image.slidesharecdn.com/bcc-100906062810-phpapp02/95/basal-cell-carcinoma-9-728.jpg?cb=1283754650
4 subtypes of malignant melanoma
- Superficial spreading [most common]
- nodular [domed shape, rapid growth]
- lentigo maligna [flat lesions often on face, elderly]
- acral lentiginous [palms, soles, nail beds, often in non-caucasians]
Skin cancer referrals
Referral
• Melanoma – urgent referral
• SCC – urgent referral
• BCC – routine referral
What are melanocytic lesions?
• Melanocytic lesions = not cancer, benign neoplasms of melanocytes in epidermis
