What is erysipelas?
A skin infection involving the dermis and superficial cutaneous lymphatics
Is more well-demarcated; firm, swollen, pruritic
Typically affects the legs or face (can be a butterfly)
Almost always caused by GAS
What is cellulitis?
Skin infection involving the dermis and the whole lymphatic cutaneous tissue
Less well-demarcated; red
Can occur anywhere but most commonly the limbs
Most commonly GAS and staph. a
Treatment of cellulitis and erysipelas
Supportive
Emollients
Abx
- flucloxacillin
- fluclox and benpen if severe
What is TEN?
Toxic epidermal necrolysis
Immune-mediated epidermolysis, often secondary to drugs or infection. This leads to exfoliation of the epidermis and mucous membranes, affecting > 30% of TBSA
This causes a significant risk of infection, sepsis and death
What is SJS?
The same as TEN except if covers a TBSA < 10%
SJS < mixed < TEN
Signs of TEN and SJS
- Flu-like pro-drome
- Erythematous rash with bullae
- Bullae coalesce to form a sheet, which can easily slough
- Nikolsky positive
- Tends to start on face and pre-sternal area, then torso, sparring scalp
Management of TEN and SJS
- Stop offending agent
- Fluids as per Parkland formula
- Refer to burns unit or ICU
What is erythema nodosum?
Panniculitis (inflammation of the subcutaneous fat), usually along the shin
Erythematous, firm solid, deep nodule, painful on palpation
Causes:
- NO - idiopathic
- D - drugs e.g., sufonamides and dapsone
- O - OCP
- U - UC and Crohn’s
- M -microorganisms e.g. TB, strep, toxo
What is erythema multiforme?
It is an immune-mediated skin lesion, which is characteristically target-like in appearance and often affects the extremities
The centre is erythematous with a blister, then a clearer and oedematous zone, with an outer zone with erythema and microvesicles
Often secondary to infection, commonly HSV. Less likely mycoplasma. Also EBV, HIV, CMV, campy and salmonellla etc. May be secondary to drugs too
What is erythroderma?
An immune-mediated exfoliative dermatitis, with lots of causes but primarily pre-existing dermatoses, malignancy, drugs and idiopathic
Erythematous patches, which coalesce to cover >90% of TBSA. They then become white/yellow plaques. Itchy. Oedema and lichenification can make the skin feel tight.
Observe and give supportive care
What’s impetigo?
Skin infection with Staph. A or Strep in areas of skin trauma, common in infants
Erythmatousmaccules that vesiculate and pustulate, that superficially erode leaving a golden crust. Bullous –> blisters and non-bullous –> sores
Local non-bullous –> hydrogen peroxide
Widespread non-bullous –> topical or oral abx for 5 days, fusidic acid/mupirocin or fluclox
Bulous –> fluclox 7 days
Keep offschool for 48 hours until abx started. Good hygeine
What is lichen planus?
A lesion caused by T-cell medicated inflamation. Cause is thought to be autoimmune but may be triggered by hep C, allergic contact dermatitis, skin infection and trauma. Occurs more often at the flexor wrist and ankle
6Ps - purple, planar, polygonal, pruritic, plaques, papules. Wickham’s striae - white lacy lines on the surface
Oral - ulceration with mottled Wickham’s striae on the gums and tongue. Lichen planopilaris - scarring alopecia with follicular papules
