Case 8 SAP Flashcards
Macule
Small flat lesion
Patch
Large flat lesion
Papule
solid raised lesion <0.5cm
Plaque
solid raised lesion >0.5cm
Vesicle
raised, clear, fluid-filled lesion <0.5cm
Bulla
raised, clear, fluid-filled lesion >0.5cm
Vasculitis
autoimmune inflammation of blood vessels. can be small, medium, or large. causes generalised inflammatory symptoms and specific symptoms depending on location of vessels
Small vessel vasculitis examples
GPA, microscopic polyangiitis, Churg-Strauss syndrome, Henoch-Schonlein purpura
Medium vessel vasculitis examples
Kawasaki disease, Polyarteritis nodosa, Buerger disease
Large vessel vasculitis examples
giant cell arteritis, Takayasu arteries
Measles virus family
morbillivirus/paramyxovirus
Initial symptoms of measles
high fever, cough, coryzal symptoms, conjunctivitis
Type of rash and spots and locations associated with measles
Maculopapular rash first to face and behind ears, spreads down the trunk with hands and feet affected last.
Kolpik’s spots (2-3mm red spots with white/blue centres) to buccal mucosa
Rubella virus family
togaviridae
Rubella rash
maculopapular rash beginning on the face, spreading onto the trunk and limbs. typically pink or light red
Other symptoms of rubella
Lymphadenopathy in the head and neck, joint pain and inflammation, low-grade fever, headache, malaise, mild URT symptoms
What can occur if a pregnant person contracts rubella?
stillbirth, miscarriage, and congenital rubella syndrome
Erythema infectiosum virus type
fifth disease/slapped cheek. caused by parvovirus B19
Erythema infectiosum rash
Slapped cheek rash, maculopapular rash to the trunk, back, and limbs that fades to form a reticular (lace-like) pattern
Other symptoms of erythema infectiosum
rash preceded by fever, coryzal symptoms, nausea. also arthralgia
Roseola virus type
human herpesvirus 6
Roseola rash
pink maculopapular rash that starts on the trunk before affecting the face and limbs
Other symptoms of roseola
runny nose, sore throat, sudden high fever
Herpes simplex virus types
HSV-1 and HSV-2
Herpes simplex virus rash
Group of vesicles that rupture leaving superficial ulcers that crust over and heal
Where does herpes simplex virus primarily affect?
inside mouth, lips, genitals, eyes, and fingers
Chickenpox virus type
varicella zoster virus
Chickenpox rash
usually in children. starts as macules which progress to papules, vesicles, and pustules. can have various stages of the rash in different places at the same time. very itchy
Shingles virus type
varicella zoster virus
Shingles rash
rash appears similar to that of chickenpox. follows dermatomal distribution (area supplied by a single nerve so typically appears as a stripe) and does not cross midline of the body. burning and stabbing pain at the affected site.
What can occur after the shingles rash has gone?
post-herpetic neuralgia
What causes Henoch-Schonlein Purpura symptoms ?
usually occurs in childhood. IgA immune complexes are present in the small blood vessel walls which triggers inflammation
HSP rash
red or purple non-blanching purpuric rash usually to the lower limbs and buttocks
Other symptoms of HSP
arthralgia, arthritis, abdominal pain, bloody diarrhoea, nausea, vomiting, proteinuria and haematuria
Kawasaki disease description
occurs in children. infection triggers an autoimmune response. can affect coronary arteries so should present to hospital
Kawasaki disease symptoms
Fever >39, red palms and soles with desquamation, conjunctivitis, inflammation of lips, tongue, and mouth, lymphadenopathy
Polyarteritis nodosa incidence and association
peak incidence aged 10 and 40-50. can be associated with hep B infection
Cutaneous signs of polyarteritis nodosa
tender nodules, skin necrosis, ulceration, livedo reticularis (mottled blue/purple discolouration) due to reduced blood supply to the skin
Which areas does polyarteritis nodosa affect?
Peripheral nerves, kidneys (hypertension or AKI), GI tract (abdominal pain after eating), and skin
Diabetic dermopathy
cause unknown but associated with damage to small vessels and nerves that occurs with diabetes. presents with oval, light brown patches that occur over bony areas possibly in response to injury
Acanthosis Nigricans
associated with insulin resistance but can also occur due to certain medication or malignancy (GI cancers). hyperpigmentation of skin especially in creases (neck, armpits, groin) and skin may thicken
Eruptive Xanthomatosis
firm, yellow, pea-like enlargements in the skin surrounded by a red halo, may be itchy. sign of uncontrolled type I diabetes and raised triglycerides
Necrobiosis lipodica diabeticorum (NLD)
starts as a dull red lesion that can then become a shiny scar with a violet border. on shin. rare, mostly seen in women
Systemic lupus erythematosus (SLE) description
multisystem autoimmune condition with unknown cause. more common in women and is relapsing and remitting in nature.
Skin symptoms of SLE
sun sensitivity, butterfly rash to the face that spares the nasolabial folds
Systemic symptoms of SLE
symmetrical arthralgia, joint stiffness, fatigue, Raynaud’s, nephritis, pericarditis, pleuritis
Describe the pathophysiology of acne
blockage and inflammation of pilosebaceous unit.
androgens increase production of sebum in enlarged sebaceous glands → follicles become impacted and distended by keratinocytes and sebum → causes comedones. proliferation of bacteria in sebum causes inflammation of pilosebaceous unit and inflammatory lesions
Which bacteria is responsible for acne?
propionibacterium acnes
Open comedones
blackheads
Closed comedones
whiteheads
Presentation of acne
open and closed comedones , inflamed papules and pustules, nodules and pseudocysts in severe, scars, psychological effects.
Categorisation of acne
based on numbers of lesions. mild <30, moderate 30-125, severe >125
Pathophysiology of eczema
Occurs with weakened skin barrier and predisposition to allergic inflammation.
Allergen gets through skin barrier → hypersensitivity reaction → skin barrier becomes more permeable and leaky → more allergen can enter and more water can escape → dry skin itches so patient scratches → skin barrier weakened further → cycle repeats itself
What genetic mutation can be associated with eczema?
decreased production of filaggrin which makes the skin barrier more permeable
Actions of filaggrin
helps convert keratinocytes to corneocytes, helps formation of lipid matrix so gives structure to stratum corneum
Which immune cell do some eczema patients have increased numbers of?
helper T
Presentation of eczema
80% before the age of 5, 60-70% resolve by early teens.
Skin: red, weeping, crusted, may blister, skin becomes thicker (lichenified) and scaly over time, fissures can occur, erythema can be violaceous in darker skin
Presentation of eczema
80% before the age of 5, 60-70% resolve by early teens.
Skin: red, weeping, crusted, may blister, skin becomes thicker (lichenified) and scaly over time, fissures can occur, erythema can be violaceous in darker skin
Nail ridging in severe
Location: infants = face and arms, older age = narrowed to flexors, hands, and ankles
Pathophysiology of psoriasis
Stimulus occurs → T cells and dendritic cells infiltrate the skin → release of pro-inflammatory cytokines like TNF-α and IL-7 → activation and proliferation of keratinocytes → erythema → keratinocytes move up through the epidermis in 3-5 days rather than the usual 21 → thickening of epidermis and thick scaly patches on the skin surface
Chronic plaque psoriasis
symmetrically distributed, red skin, scaly plaques with well-defined edges, typically silvery white on the surface. Itching can lead to lichenification. Persistent and can resist treatment. Plaques tend to be >3cm. Found mostly on elbows, knees, lower back, and scalp. Coverage can be mild or very extensive. Plaques can become unstable after skin injury, infection, stress, drugs, or drug withdrawal
Guttate psoriasis
usually post strep throat. Widespread small plaques and raised papules, usually across torso and back
Flexural psoriasis
found in body folds and genitals, smooth and well-defined, colonised by candida yeast.
Sebopsoriasis
overlap of seborrheic dermatitis and psoriasis. Found on scalp, face, ears, and chest. Colonised by Malassezia yeast
Palmoplantar psoriasis
palms and soles, keratoderma, and painful fissuring
Nail psoriasis
pitting, onycholysis, yellowing, ridging. Associated with inflammatory arthritis
Erythrodermic psoriasis
rare, acute or chronic, and may result in systemic illness with temperature dysregulation, electrolyte imbalance, and cardiac failure
Exacerbating factors of psoriasis
strep infections, injuries (Koebnerised psoriasis), dry skin, obesity, smoking, excessive alcohol, stress, medications, and stopping steroids
Biological impact of living with skin disease
scarring, hyperpigmentation, treatment side effects, itch, peeling skin, and sleep deprivation.
Psychological impact of living with skin disease
frustration, anger, depression, anxiety, suicide, low self-esteem, poor body image, and restriction of clothing choices
Social impact of skin disease
isolation, poor school performance, restricted activities e.g. swimming, limited pet choice, career choice and performance, frequent hospital visits, and relationships and sex
Define antibiotic stewardship
an organisational or healthcare-system-wide approach to promoting and monitoring judicious use of antimicrobials to preserve their future effectiveness
Principles of antibiotic stewardship
Prescriber should follow local and national guidelines on prescribing the shortest effective course of the most appropriate dose and route of administration. Prescribers should keep aware of prescribing levels, patient safety incidents, and should be educated and trained effectively. Do not initiate antibiotic treatment in the absence of bacterial infection
Describe the basis on which antibiotic choice is made in clinical practice
Antibiotics should be given on the shortest course, with the lowest possible dose, and the best route of administration.
Should check with microbiology in hospital settings, primary care with recurrent infections, and non-severe infections with diagnostic uncertainty to give the best possible choice.
Check patient allergies, other illnesses, and contraindications with other medications and food/drink.
Broth dilution test
inoculate different dilutions of antibiotic with the bacteria. The lowest dilution with no growth is the MIC
Disk diffusion test
measure clear radius around a disk of antibiotic. Bigger clearance = bacteria more susceptible to that antibiotic. Grouped into resistant, intermediate, and susceptible.
Antimicrobial gradient test
MIC determined by intersection of growth with strip as measured using scale on strip.
