Case 8- skin diseases Flashcards
Impetigo pathogen
Staphylococcus aureus and occasionally Streptococcus pyogenes.
Impetigo- general
An acute, superficial skin infection that mainly affects people 0-4 and to a lesser extent 5-14yrs. It is either a primary condition or secondary to eczema, scabies and trauma. Transmission is via close contact or through infected objects like toys. There are two types bullous (70%) and non-bullous. Bullous refers to 1cm filled blister
Impetigo- presentation
Thin pustules or vesicles which break, forming a honey coloured crust. There will be mild erythema (reddening of the skin) and will heal without scarring. It is most commonly on exposed area like face and hands. Individuals can have associated lymphadenopathy, malaise and a mild fever.
Impetigo- treatment for localised non-bullous impetigo
Use hydrogen peroxide (1% cream), if it doesn’t work use a short course of topical antibiotics. If impetigo becomes widespread offer a short course of topical or oral antibiotics
Impetigo - treatment for widespread non-bullous impetigo
A short course of topical or oral antibiotics (fuisidic acid 2% cream)
Impetigo- treatment for Bullous impetigo / systemically unwell / high risk of complications
Offer a short course of oral antibiotics
Example of a topical antibiotic
Fusidic acid (2%) cream
Complications of impetigo
Impetigo can be serious in neonates and immunocompromised patients leading to life threatening complications. The complications; Cellulitis, Guttate psoriasis, Scarlet fever and Septicaemia
Cellulitis pathogen
Staphylococcus aureus
Cellulitis
A spreading bacterial infection of the deeper dermis and subcutaneous tissue
Cellulitis risk factors
Previous cellulitis, skin breaks, immunocompromised, oedema and obesity
Cellulitis presentation
pain, swelling (slightly raised), warmth, erythema (usually more diffuse)- infection is deeper in the dermis. It causes blisters or bullae. You may be systemically unwell with fever, malaise, rigors indication a deep seated infection, abscess or source of sepsis.
Pereorbital cellulitis
Inflammation and infection of the eyelid and skin around the eye anterior to the orbital septum. You should admit these patients to hospital to rule out orbital cellulitis which is a serious condition which can result in visual loss and meningitis
Cellulitis treatment systemically well
At home you receive a high dose of oral flucloxacillin. You draw around the erythema and add a date so you can see the progression or recession when examining the area again.
Cellulitis treatment- systemically unwell or comorbidities
At hospital you receive IV flucloxacillin. You draw around the erythema and add a date so you can see the progression or recession when examining the area again.
What does antibiotic choice depend on for a skin infection
If it is a recurrent infection, contamination levels (i.e. by seawater), the site e.g. eyes and nose, if it is an atypical infection.
Erysipelas pathogen
Streptococcus pyogenes
Erysipelas
A superficial form of cellulitis in the upper dermis. It is typically on the face or a butterfly pattern on the lower limbs
Erysipelas risk factors
Previous erysipelas, skin breaks, being immunocompromised, oedema and obesity
Erysipelas presentation
Pain, swelling (raised), warmth, erythema (well demarcated), infection is more superficial when compared to cellulitis. There will be blisters or bullae. More likely to be systemically unwell when compared to cellulitis with fever, malaise and rigors. Well bordered.
Treatment for erysipelas
- First choice antibiotic- Flucloxacillin 500mg
- If allergic to penicillin- Clarithromycin 500mg
- If near eyes or nose- Co-amoxiclav
Preventing cellulitis or erysipelas
You should not routinely offer antibiotic prophylaxis to prevent cellulitis or erysipelas. If you do offer phenoxymethylpenicillin 250mg twice a day or erythromycin 250mg twice a day for penicillin allergy.
Necrotising fasciitis pathogen
Group A haemolytic streptococcus, Polymicrobial, Clostridium and marine organisms.
Necrotising fasciitis
A rapidly spreading infection of the deep fascia
Necrotising fasciitis risk factors
Abdominal surgery, diabetes and malignancy. 50% of infections are in previously healthy individuals
Types of necrotising fasciitis
- Fournier’s gangrene- affecting the perineal, genital and perianal region
- Ludwig’s angina- affecting submandibular space
Presentation of necrotising fasciitis
Severe pain which stops when the nerves are destroyed, purple rash, blisters filled with dark fluid, necrosis, oedema, crepitus (gas in tissue) and as critically unwell (fever, hypotension and tachycardia).
Treatment for necrotising fasciitis
Intravenous antibiotics, make sure blood cultures have been taken. You will also need fluid resuscitation, urgent referral for extensive debridement by plastic surgeons. Hyperbaric oxygen chambers can be used with Clostridium infections to stop toxin production. Mortality is up to 76% and it will require reconstruction and skin grafts. The most serious skin infection.
Hair follicle infection pathogen
S.aureus
Hair follicle infection risk factors
Male, adolescent, contact sport, poor personal hygiene, pre-existing skin conditions, steroids, immunosuppression, obesity and malnutrition.
Folliculitis
Superficial infection of the hair follicles causing papules and pustules
Furuncles (boils)
Deeper infection of the hair follicle extending through the dermis and into the subcutaneous tissue where abscess’s form
Carbuncles
The furuncles join into a mass with purulent drainage from multiple follicles
Pseudofolliculitis
Inflammation due to ingrown hair
Treatment for a hair follicle infection
Apply heat to the area, Analgesia (pain killers), good personal hygiene measured. May need IV antibiotics and admission if systemically unwell or oral antibiotics at home. In fluctuant furuncle or carbuncle refer to surgeons for incision and drainage.
Maculopapillary rash
Consists of macules which are flat lesion less then 1.5cm and papules, a solid raised lesion smaller than 05cm.
Measles
In the Paramyxoviridae family, early symptoms of high fever and the 3 C’s cough, coryza an conjunctivitis. Coryza is inflammation and irritation of the mucus membrane in the nose. You then get a Maculopapular rash.
Vesicles
A raised, clear, fluid filled lesion which is less than 0.5cm
Rubella
In the Paramyxoviridae family. Early symptoms of Lymphadenopathy (disease affecting the lymph nodes) in the head and neck. You then get a Maculopapular rash, it spreads from the face to the trunk and to the limbs.
Parvovirus
Other name for the infection is Erythema infectiosum, fifth disease and slapped cheek disease. Its early signs are fever, coryza and nausea. You then get a slapped cheek rash, a Maculopapular rash to the trunk and arthritis.
Herpes simplex virus
- HSV1- oral or genital herpes.
* HSV2- genital herpes
Varicella zoster virus (VSV)
1) Chickenpox- usually in children
2) Shingles- more common in adults who are immunosuppressed. There is reactivation of the virus after initial infection
Causes of Vesicular rash
A rash caused by a viral infection. Caused by chicken pox, shingles, Enterovirus and Poxvirus
Vasculitis
Inflammation of blood vessels, either arteries or veins. It is due to an autoimmune disease. It can be divided on the size of the vessel affected
Types of vasculitis
- Small- Granulomatosis with polyangiitis (GPA), microscopic polyangiitis, Henoch-Schonlein purpura (HSP).
- Medium= Kawasaki disease, Polyarteritis nodosa
- Large= Giant cell arteritis, Takayasu arteritis.
Vasculitis pathology
Blood vessels become damaged leaving them prone to aneurysm, increases the chance of coagulation and produces fibrous vessel wall. The difference between the types of vasculitis are their triggers and where they cause pathology. Generalised symptoms are due to inflammation on the body. The specific symptoms depend on the location i.e. affected vessels can cause ischaemic damage to the organs they supply.
Henoch-Schonlein purpura
Usually occurs in childhood. IgA immune complexes are present in the small blood vessels which trigger inflammation
Presentation of Henoch- Schonlein purpura
- Skin- purpuric rash (red or purple, non-blanching) usually to the back of legs.
- Joints- knees and ankles
- GI tract- abdominal pain, bloody diarrhoea, nausea and vomiting
- Kidneys- proteinuria and haematuria
Kawasaki disease
Occurs in children, thought to be due to an infection triggering an autoimmune response. It presents with a fever higher at 39 degree, a rash- red palms and soles with skin peeling away (desquamation). You get conjunctivitis and inflammation of the lips, tongue and mouth. It presents with Lymphadenopathy. It can affect the coronary arteries so suspected cases should present to hospital.
Polyarteritis Nodosa
Peak incidence is at 10 years and between 40-50 years. You can have a systemic or cutaneous (less severe forms). Can be associated with a Hepatitis B infection. Cutaneous signs include tender papules and plaques, purpura (purple, non-blanching lesions), livedo reticularis (net-like mottled appearance to the skin), skin necrosis and ulceration.
What does Polyarteritis Nodosa effect?
- Peripheral nerves.
- Kidneys- hypertension or acute kidney injury.
- GI tract- abdominal pain after eating
- Skin- legs and feet.
Endocrine infection- diabetic dermopathy
Unknown cause, it is associated with damage to small blood vessels and nerves which occurs in diabetes. Dermopathy forms oval, light brown patches. It occurs over bony areas, it can form in response to injury in these areas. There is no treatment.
Endocrine infection- Acanthosis Nigricans
Visualisation of insulin resistance, it also occurs due to certain medications or due to Malignancy’s (GI cancers). There is hyperpigmentation of skin especially in creases- neck, armpits and groin. Skin can become thicker.
Endocrine infection- Eruptive xanthomotosis
A firm, yellow, pea like enlargement of the skin. It has a red halo and may be itchy. It is a sign of uncontrolled type 1 diabetes, often in young and people with raised triglycerides. Treatment would be diabetes management.
Endocrine infection- Necrobiosis lipoidica diabeticorum (NLD)
NLD starts as a dull, red lesion then becomes a shiny scar with a violet border. It occurs on the shin and is a rare condition which is mainly seen in women. No treatment is recquired unless there are open sores.
Connective tissue infection- Systemic lupus erythematosus (SLE)
Autoimmune condition with an unknown cause. Anti-nuclear antibodies (ANA) are present in most cases. It is more common in woman. Is relapsing and remitting in nature
Presentation of systemic lupus erythematosus (SLE_
- Skin- sun sensitivity, butterfly shaped rash to the face.
- MSK- peripheral, symmetrical joint pain and stiffness.
- Fatigue
- Raynaud’s phenomenon- temporary reduction in blood supply to fingers and toes,
- Kidney- nephritis
- Heart- pericarditis
- Lungs- pleuritis
