Dermatology - Emergencies Flashcards
1
Q
What is erythoderma?
A
- Overview: exfoliative dermatitis involving at least 90% of the skin surface
- RFs: previous skin disease (eczema, psoriasis), lymphoma, drugs (sulphonamides, penicillin, allopurinol, captopril), idiopathic
- Presentation: inflamed, oedematous and scaly skin, systemically unwell with lymphadenopathy and malaise. Acute deteriorations require hospital admission.
- Erythrodermic psoriasis – chronic disease progresses to exfoliative phase with plaques covering most of the body.
2
Q
How is erythoderma mxd?
A
Tx underlying cause if known, emollients + wet-wraps to maintain skin moisture
Topical steroids to relieve inflammation
3
Q
What are some complications of erythoderma?
A
- secondary infection
- fluid loss and electrolyte imbalance (skins regulatory function diminished)
- hypothermia,
- high-output cardiac failure
- capillary leak syndrome.
- Death – 20-40% depending on cause.
4
Q
What is eczema herpeticum?
A
- Overview: widespread eruption that occurs as a complication of atopic eczema or other skin conditions (thermal burns, pemphigus vulgaris). Manifestation of a disseminated viral infection.
- Cause: Herpes simplex virus (HSV1/2)
- Presentation: extensive crusted papules, blisters and erosions. Systemically unwell with fever and malaise.
5
Q
What is the mx of eczema herpeticum + complications?
A
- Mx: IV acyclovir + abx + admission for secondary bacterial infection.
- Complications: herpes hepatitis, encephalitis, DIC, death.
6
Q
What is necrotizing fascitis?
A
Overview: life-threatening bacterial infection of the soft tissue and fascia.
- Type I = polymicrobial (Staph +/- haemophilus +/- E.coli)
- Type II = haemolytic group a strep +/- MRSA
- Type III = gas gangrene due to Clostridium perfringens.
7
Q
What are some RFs for necrotizing fascitis?
A
- Aspirin
- NSAIDs,
- increasing age
- immune suppression,
- obesity
- drug abuse,
- chronic illness
- malignancy.
8
Q
How does necrotizing fascitis arise?
A
- Infection begins in the superficial fascia, bacteria release enzymes and proteins that result in necrosis of fascial layers.
- Horizontal spread of infection followed by vertical spread.
- Thrombosis occludes arteries and veins leading to ischaemia and necrosis.
9
Q
How does necrotizing fasciittisi present?
A
- Lower leg most common, symptoms present <24h of minor injury, pain is very severe at presentation and worsens over time.
- Purplish rash, large dark marks that turn into blisters filled with dark fluid. Wound starts to die and area becomes necrotic.
- Fine crackling sensation ‘crepitus’ due to fas in the tissues
- Dishwasher coloured fluid seeps out of skin
- Flu like symptoms, nausea, fever, diarrhoea, general malaise
- If untreated, infection can spread to bloodstream > dangerously low BP, high temp.
10
Q
How is nectrozing fascitis ixd + mxd?
A
- Ix: WBC, CRP, CK, Urea (all raised), U&Es – low sodium
- Blood cultures, deep tissue biopsy, gram stain to ID organism
- Mx:
- Hospitalisation > ICU (A-E)
- High dose IV abx (penicillin, clindamycin, metronidazole, vancomycin…)
- Urgent surgical debridement, may require amputation
- Hyperbaric oxygen and IVIg may be considered.
11
Q
What is erythema multiforme and how does it present?
A
Overview: hypersensitivity reaction triggered by infections. Typically affects young adults. Major and minor forms.
Presentation:
- Several -100s of skin lesions erupt within 24h. first seen on backs of hands or tops of feet then spread towards the trunk. Polymorphorous (eruption at various stages of development)
- Well demarcated, round, red/pink, macules that progress to papules and then enlarge to form plaques.
- ‘Iris lesion’- sharp margin, regular round shape, and three concentric zones
- Minor: mucus membrane involvement is absent or mild.
- Major: one or more mucus membranes are affected, most often the oral mucosa – swelling with blister formation.
12
Q
What are some of the causes of erythema multiforme?
A
- viruses: HSV (the most common cause), Orf*
- idiopathic
- bacteria: Mycoplasma, Streptococcus
- Drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, oral contraceptive pill, nevirapine
- Connective tissue disease e.g. SLE
- sarcoidosis
- malignancy
13
Q
How is erythema multiforme mxd?
A
- Oral acyclovir for HSV, abx (erythromycin) for Mycoplasma.
- Stop offensive drug.
- Supportive tx – antihistamine, topical corticosteroids, mouthwashes containing LA
14
Q
What is Stevens Johnsons syndrome?
A
- Overview: rare, potentially life-threatening skin reaction involving sheet-like skin and mucosal loss. Very rare complication of medication use.
- Mucocutaneous necrosis >/=2 sites affecting <10% of body.
Presentation
- Fever >39C, sore throat, difficulty swallowing, runny nose, cough, conjunctivitis, general aches and pains.
- Abrupt onset tender, painful red skin rash starting on the trunk and extending rapidly onto the face and limbs.
- Macular, background erythema, targetoid (as in EM), and flaccid blisters.
- Blisters merge to form sheets of skin detachment. Nikolsky sign +ve (when rubbed gently will burst)
- Mucosal involve prominent and severe.
15
Q
What medicaitons cause stevens johnsons
A
- penicillin
- sulphonamides
- lamotrigine, carbamazepine, phenytoin
- allopurinol
- NSAIDs
- oral contraceptive pill
18
Q
What is Staphylococcal Scalded Skin Syndrome?
A
- Looks like a burn or scald.
- Pathophysiology: release of exotoxins (A+B) from toxigenic strains of Staph aureus.
- Toxins bind to a desmoglein 1 within the desmosomes that adhere skin cells together
- > Break it up and as a result the skin cells become unstuck
*
25
Q
How does pemphigus vulgaris present/?
A
- Most patients first present with lesions on mucous membranes such as the mouth and genitals. Blisters usually develop on the skin after weeks-months
- Thin walled flaccid blisters with clear fluid that rupture easily (+ ve Nicholskys sign)
- -> Causes itchy, painful erosions which can be painful, and clow to heal.
- Inside of the mouth commonly involved.
28
Q
How does dermatitis herpetiformis present?
A
- Symmetrical distribution of extremely itchy papules and vesicles on normal or erythematous skin.
- Lesions appear of scalp, shoulders, buttocks, elbows and knees.
- Often appear in groups or clusters.
