Eczema, Psoriasis & Impetigo Flashcards
What is the most common form of psoriasis?
Chronic plaque psoriasis
Clinical features of psoriasis?
Erythematous plaques covered with a silvery-white scale
Typically on the extensor surfaces such as the elbows and knees.
Also common on the scalp, trunk, buttocks and periumbilical area
What is Auspitz’s sign?
If the scale in psoriasis is removed, a red membrane with pinpoint bleeding points may be seen.
1st line mx of chronic plaque psoriasis?
Potent corticosteroid applied once daily
plus
Vitamin D analogue applied once daily for up to 4 weeks
N.B. Regular emollients may help to reduce scale loss and reduce pruritus
How should corticosteroid & vitamin D analogue be applied in psoriasis?
These should be applied separately, one in the morning and the other in the evening
2nd line mx of chronic plaque psoriasis?
If no improvement after 8 weeks then offer a vitamin D analogue twice daily
Complications of psoriasis?
1) Psoriatic arthropathy (around 10%)
2) Increased incidence of metabolic syndrome
3) Increased incidence of cardiovascular disease
4) Increased incidence of venous thromboembolism
5) Psychological distress
What is atopic dermatitis AKA?
Eczema
What is the cardinal symptom of eczema?
Pruritus
Diagnostic criteria for eczema?
An itchy skin condition in the last 12 months
Plus three or more of
1) Onset below age 2 years
2) History of flexural involvement
3) History of generally dry skin
4) Personal history of other atopic disease
5) Visible flexural dermatitis
What age of onset is required to diagnose eczema?
Onset <2 y/o
What is involved in mx of eczema?
1) Emollients
2) Topical steroids
3) Topical calcineurin inhibitors
4) Antimicrobials
5) Phototherapy
6) Systemic therapies
7) Biologic therapy
When are topical steroids indicated in eczema?
Acute flares & moderate to severe eczema
Give an example of a lower potency topical corticosteroid that can be used on delicate areas such as the face or genitals?
Hydrocortisone 1%
Give an ecample of a topical calcineurin inhibitor
Tacrolimus
Role of topical calcineurin inhibitors in eczema?
An alternative to steroids.
They are particularly useful in areas where long-term steroids use is contraindicated, such as the face or skin folds.
What is eczema herpeticum?
Widespread 2ary HSV-1 or 2 infection, which typically affects people with atopic dermatitis or eczema.
Can also affect those with other inflammatory condiitons.
Risk factors for eczema herpeticum?
1) Early-onset or more severe atopic dermatitis
2) Head and neck or large body surface area involved dermatitis
3) High total serum IgE/ peripheral eosinophilia
4) Atopic comorbidities such as asthma and food allergies
5) History of Staphylococcus aureus skin infection
6) Other associations include younger age and non-white ethnicity, particularly African American and Asian.
It can also be triggered by trauma or cosmetic procedures e.g. lasers, skin peels, dermabrasion.
Clinical features of eczema herpeticum?
1) Areas of rapidly worsening, painful eczema
2) Vesicular rash
3) Punched-out erosions (circular, depressed, ulcerated lesions) usually 1-3mm that are uniform in appearance (monomorphic)
4) Possible fever, lethargy, lymphadenopathy or distress
Referral indicated in any cases where eczema herpeticum is suspected?
1) Referral to a specialist paediatric dermatologist
2) Eczema herpeticum involving the skin around the eyes should be referred for same-day ophthalmology review
Referral regarding eczema herpeticum involving the skin around the eyes?
Refer for same day opthalmology review
How can eczema herpeticum affect the eyes?
HSV may spread to the eye resulting in herpes keratitis.
This can result in scarring –> prompt ophthalmological referral.
Investigations if herpetic keratitis is suspected?
Staining with fluorescein –> stained dendritic ulcer is diagnostic
Mx of eczema herpeticum?
Derm emergency!
Oral or IV aciclovir
Mx of ocular involvement in eczema herpeticum?
Ganciclovir ointment
N.B. A corneal transplant may be indicated in cases of postherpetic scarring that significantly affects vision
What % of 50% of patients with eczema herpeticum experience recurrence?
50%
What is the most common complication of eczema herpeticum?
2ary bacterial infection:
1) Staph. aureus –> impetigo
2) Strep –> cellulitis
Complications of eczema herpeticum?
1) 2ary bacterial infection
2) Scarring
3) Herpetic keratitis
4) Organ failure and dissemination
What are the 2 main types of contact dermatitis?
1) irritant contact dermatitis
2) allergic contact dermatitis
What is irritant contact dermatitis?
Non-allergic reaction due to weak acids or alkalis (e.g. detergents).
Often seen on the hands.
Erythema is typical, crusting and vesicles are rare
What is allergic contact dermatitis?
Type IV hypersensitivity reaction.
Often seen on the head following hair dyes.
How does allergic contact dermatitis typically present?
Presents as an acute weeping eczema which predominately affects the margins of the hairline rather than the hairy scalp itself.
Mx of allergic contact derm?
Potent topical steroid
What substance is a frequent cause of contact derm?
Cement
The alkaline nature of cement may cause an irritant contact dermatitis whilst the dichromates in cement also can cause an allergic contact dermatitis
What is impetigo?
A superficial BACTERIAL infection.
What 2 organisms typically cause impetigo?
1) Staph. aureus
2) Strep. pyogenes (GAS)
Spread of impetigo?
Direct contact with discharges from the scabs of an infected person
Features of impetigo?
1) ‘golden’, crusted skin lesions typically found around the mouth
2) very contagious
Mx of impetigo?
1) hydrogen peroxide 1% cream –> if NOT systemically unwell or at a high risk of complications
2) topical abx e.g. fusidic acid
1st line mx of impetigo?
Hydrogen peroxide 1% cream
Mx of extensive disease in impetigo?
Oral flucloxacillin (or erythromycin if allergic)
School exclusion in impetigo?
Until the lesions are crusted and healed or 48 hours after commencing antibiotic treatment.
What are some factors that predispose to pressure ulcers?
1) malnourishment
2) incontinence: urinary or faecal
3) lack of mobility
4) pain (leads to a reduction in mobility)
What score is widely used to screen for patients who are at risk of developing pressure areas?
Waterlow score
Describe a Grade 1 pressure ulcer
Non-blanchable erythema of intact skin. Discolouration of the skin, warmth, oedema, induration or hardness may also be used as indicators, particularly on individuals with darker skin
Describe a Grade 2 pressure ulcer
Partial thickness skin loss involving epidermis or dermis, or both.
The ulcer is superficial and presents clinically as an abrasion or blister
Describe a Grade 3 pressure ulcer
Full thickness skin loss involving damage to or necrosis of subcutaneous tissue that may extend down to, but not through, underlying fascia.
Describe a Grade 4 pressure ulcer
Extensive destruction, tissue necrosis, or damage to muscle, bone or supporting structures with or without full thickness skin loss
Mx of a pressure ulcer?
1) a moist wound environment (encourages ulcer healing)
2) hydrocolloid dressings and hydrogels
3) wound swabs frequently
What can guttate psoriasis be precipitated by?
Strep infection 2-4 weeks prior to the lesions appearing
1st line mx of moderate-severe psoriatic arthritis?
Standard DMARDs e.g. methotrexate, leflunomide or sulfasalazine
What is tinea corporis?
A superficial fungal infection of the skin, often referred to as ringworm.
Cause of tinea corporis?
It is NOT caused by a worm.
The condition is primarily caused by dermatophytes, a group of FUNGI that thrive on keratin, a protein found abundantly in the skin, hair, and nails.
Clinical features of tinea corporis?
Presents as erythematous, scaly plaques with an active, advancing, and often pruritic border.
The centre of the lesion may clear up as it expands, resulting in a characteristic ring-like appearance, hence the name ringworm.
Mx of tinea corporis?
Topical antifungal medication such as clotrimazole or terbinafine.
