Dermatological Emergencies Flashcards
What is erythroderma?
Intense and widespread reddening of the skin due to inflammation - can also be known as exfoliative dermatitis. Idiopathic erythroderma is sometimes called ‘red man syndrome’.
What are common causes of erythroderma?
- Drug eruption: allopurinol, abx, antiepileptics, Ca channel blockers, opiates, isoniazid, thiazides
- Dermatitis, especially atopic dermatitis
- Psoriasis, especially after withdrawal of systemic steroids
- Pityriasis tubra pilaris (group of rare skin disorder that present with reddish orange coloured scaling patches with well-defined border)
What other skin diseases less frequently cause erythroderma?
- Contact dermatitis, stasis dermatitis (venous eczema) and in babies, seborrhoeic dermatitis or staphylococcal scalded skin
- Pemphigus or bullous pemphigoid
- Sezary syndrome (erythrodermic form of cutaneous T cell lymphoma)
- Several rare congenital ichthyotic conditions
What are signs and symptoms of erythroderma?
- Warm skin
- Itchy with lichenification
- Eyelid swelling can cause ectropion
- Scaling starts 2-6 days after onset of erythema as fine flakes or large sheets
- Thick scaling on scalp with hair loss or even complete baldness
- Swollen lymph nodes
What clues can be present in erythroderma for identifying the underlying cause?
- Serous ooze - clothes and dressings stick to skin and an unpleasant smell - atopic erythroderma
- Persistence of circumscribed scaly plaques in certain sites like elbows and knees - psoriasis
- Islands of sparing, follicular prominence, orange-hue to keratoderma - pityriasis rubra pilaris
- Subungual hyperkeratosis, crusting on palms and soles and burrows - crusted scabies
What systemic symptoms can be present in erythroderma?
- Lymphadenopathy, hepatosplenomegaly, abnormal liver dysfunction and fever - may suggest drug hypersensitivity syndrome or malignancy
- Leg oedema may be due to inflamed skin, high output cardiac failure (heart is pumping normal amount of blood, but it is not enough to help the body work as it should) +/or hypoalbuminaemia
What are the complications of erythroderma?
- Heat loss - hypothermia
- Fluid loss - electrolyte imbalance and dehydration
- Red skin - high output cardiac failure
- Secondary skin infection - impetigo, cellulitis
- General unwellness - lead to pneumonia
- Hypoalbuminaemia - due to protein loss and increased metabolic rate causes oedema
- Longstanding erythroderma may result in pigmentary changes (brown +/or white skin patches)
What is impetigo?
Bacterial infection of superficial skin, presents as yellow crusts on face, arms or legs
How is erythroderma diagnosed?
- > 20% of circulating sezary cells suggest sezary syndrome (aggressive form of cutaneous T cell lymphoma - group of disorders that occur when T cells become cancerous and affect the skin)
- Proteins may show hypoalbuminaemia and abnormal LFTs
- Polyclonal gamma globulins are common and raised IgE is typical of idiopathic erythroderma
- Skin biopsies may be taken if cause is unknown, tends to show non-specific inflammation on histopathology
- Direct immunofluorescence is of benefit if an autoimmune blistering disease or CTD is considered
What is the treatment for erythroderma?
- Discontinue all unnecessary medications
- Monitor fluid balance and body temperature
- Maintain skin moisture with wet wraps, other types of wet dressings, emollients and mild topical steroids
- Abx for bacterial infection
- Antihistamines for itch
- If cause can be identified then specific treatment should be started, such as topical and systemic steroids for atopic dermatitis, acitretin or methotrexate for psoriasis
What is SJS/TENs?
Severe skin reaction typically triggered by specific medicines. SJS is the less severe form of the disease (10% of skin affected), TENs is the most severe form (>30% of skin affected). It is a type 4 hypersensitivity reaction. Both the mucosal lining and skin affected.
What are the signs and symptoms of SJS/TENs?
- Fever
- Early: flu-like symptoms - sore throat, cough, red eyes, tender pink skin
- Macule, dark red centre, shaped lesions, also fluid filled vesicles, may get flaccid bullae
- Skin starts peeling off, leaving painful raw areas called erosions (resembles hot water burns)
- Rubbing skin can cause peeling - Nikolysky’s sign
- Leads to - fluid loss, dehydration, pneumonia, sepsis, shock, multiple organ failure
- Diagnosis is made on symptoms, but biopsy can give definitive diagnosis
What are the long term effects of SJS/TENs?
- Changes in skin colouring (pigmentation), dryness of skin and mucous membranes (xerosis), excess sweating (hyperhidrosis), hair loss (alopecia) and abnormal growth/loss of finger nails and toenails
- Other chronic problems - impaired taste, difficulty urinating and genital problems
- A minority develop throat dryness/inflammation of eyes which can lead to increased sensitivity to light (photophobia) and vision impairment
What are causes of SJS/TENs?
- HLA-B gene most commonly associated with SJS/TENs
- In a process not well understood, the medication causes cytotoxic T cells and NK cells to release a substance called granulysin that destroys cells in the skin and mucous membranes
- Certain medications
- Pneumonia due to mycoplasma pneumonia and viral infections (including CMV) has caused SJS/TENs
- Cause not fully understood
What medications can cause SJS/TENs?
- Seizure medications (carbamazepine, lamotrigine, phenytoin etc)
- Allopurinol
- Antibiotic class - penicillin, sulphonamides
- Nevirapine (treats HIV)
- Sulfasalazine (treats IBD)
- Oxicams (type of NSAID -cam)
- OCP
