Disease Profile: Other Flashcards
Describe the first line management of mild-moderate acne
Topical treatment for 3/12 then review - benzoyl peroxide or retinoids +/- topical antibiotic
Name three drugs associated with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)
Antibiotics (penicillin, sulfonamides, cephalosporins), carbamazepine, phenytoin
Why is biotin important?
Essential co-factor for carboxylase enzymes
Describe the clinical presentation of vitamin B2 deficiency
Cheilosis, angular stomatitis, painful red dry tongue
What is acute generalised exanthematous pustulosis?
Drug reaction involving widespread rash with numerous small, non-follicular, sterile pustules around the neck, axillae and groin
Usually starts a few days after drug exposure and resolves with peeling
What is discoid eczema?
Ezcema which occurs in circular or oval patches, patients often atopic, very often infected
Describe the management of a drug eruption
Discontinue drug if possible
Topical steroids may help
Antihistamines may help if type I or with symptoms of itch
Name 3 options for the management of eczema in secondary care
Phototherapy - mainly, systemic immunosuppression, biological agents (for atopic - target IL-4/IL-13)
Why is skin prick testing not first line for testing of allergy if it is more specific and sensitive?
Anaphylaxis risk
Describe the clinical features of a type II allergic adverse drug reaction
Cytotoxic reactions - pemphigus and pemphigoid
Describe the pathophysiology of contact irritant dermatitis
Non-specific physical irritation rather than a specific allergic reaction e.g. soap, water, cleaning products, water, nappy rash, ‘lip-lick’ chelitis
Describe the clinical presentation of acne
Non-inflammatory lesions (comedones) - blackheads and whiteheads
Inflammatory lesions - papules, pustules, cysts, nodules on an erythematous base
When are mild topical steroids indicated in psoriasis?
Flexural disease, palmar plantar disease and scalp psoriasis
What occurs in the allegic stage of a type I hypersensitivity (allergy)?
On re-exposure to allergen, the allergen will bind to IgE coated mast cells → cell degranulation (release of histamine and other inflammatory mediators)
What is a cutaneous drug eruption?
Adverse drug reaction of the skin - can be immunologically mediated (allergic) or non-immulogically medicated (non-allergic)
How would you manage a patient under 12 with mild-moderate acne which has not improved after 3 months of topical therapy?
Erythromycin or clarithromycin BD
Describe the clinical presentation of acute eczema
Papulovesicular, erythematous lesions, itch, ill-defined, oedema, ooze/scaling/crusting
What causes venous (stasis) dermatitis?
Incompetent veins in the leg, commonly due to increased venous pressure by obesity, leak RBCs into the tissue resulting in swelling, haemosiderin, pigmentation and inflammation
Describe the clinical presentation of psoriasis
Symmetrically distributed, red scaly plaques with well-defined edges, itching
Commonly on scalp, elbows and knees
What is the diagnostic criteria for atopic eczema?
Itching + 3 or more of:
Visible flexural rash
History of flexural rash
Personal/family history of atopy
Generally dry skin
Onset before age 2
What should all patients with type I hypersensitivity (allergy) be given to use in the event of anaphylaxis?
Adrenaline autoinjector
How would you define acne that consists of scattered comodones, papules and pustules?
Mild
What is the safest method of investigating a type I hypersensitivity (allergy)?
Specific IgE blood test
What are target lesions?
Annular shaped macules that are raised with a red rim and centre with a wedge of normal skin inbetween; feature of erythema multiforme and toxic epidermal necrolysis
Which investigation would you perform in suspected contact allergic dermatitis?
Patch testing
When would you consider a wound swab of a leg ulcer?
If ulcer increasingly painful/exudate/malodour/enlarging
How would you define acne that consists of numerous papules, pustules and mild atrophic scarring?
Moderate
What is sebopsoriasis?
Overlap of seborrhoeic dermatitis and psoriasis, affects scalp, face, ears and chest, colonised by malassezia
Describe the clinical features of a type IV allergic adverse drug reaction
T cell-mediated delayed hypersensitivity reactions - erythema/rash
Name three drugs associated with acneiform drug eruptions
Glucocorticoids (steriod acne), androgens, lithium
When is dithranol indicated in psoriasis?
Short contact regiments for stable chronic plaque disease
Describe the histology of lichen planus
Irregular sawtooth acanthosis
Hypergranuloss and orthohyperkeratosis
Band-like upper dermal infiltrate of lymphocytes
Basal damage with formation of cytoid bodies
Describe the clinical presentation of a dermatofibroma
Unchanging firm lesion, skin-coloured or brownish
Occasionally itchy
Where is acne most common and why?
Distribution reflects sebaceous gland sites - face, upper back, anterior chest
When would you consider systemic treatment in mild-moderate acne?
Poor response to topical treatment at 3 month review
How may you identify the drug behind a cutaneous drug eruption if the causative drug is not obvious from history/examination?
If suspect phototoxic drug reactions - phototesting
Biopsies can identify type of drug reaction and exclude other diseases
Patch and photopatch test, skin prick testing
How might you investigate a suspected dermatofibroma if you aren’t certain enough to diagnose clinically?
Dermoscopy, biopsy
What causes dyshidriotic eczema (pompholyx eczema)?
Occurs when there is a very sudden acute flare up of eczema and the spongiotic vesicles join together, resulting in the formation if intensely itchy tiny blisters developing in the hands and feet
What is the second-line treatment for a patient with type I hypersensitivity (allergy)?
Corticosteriods
When is systemic (immune) therapy indicated in psoriasis?
Severe or non-responsive disease
Describe the pathophysiology of venous ulcers
- Elevation of venous pressure in the legs e.g. by abdominal obesity which resists venous return from the legs
- Veins dilate and valves become incompetent, varicose veins develop
- Increased hydrostatic pressure in the vessels → red blood cell leakage into the tissue resulting in swelling, haemosiderin, pigmentation and inflammation
- The skin cannot heal well due to poor blood supply, so begins to break down
What lifestyle advice would you give to a patient with type I hypersensitivity (allergy)?
Allergen avoidance
What causes arterial leg ulcers?
Insufficient blood supply due to peripheral vascular disease
Name three drugs associated with drug reaction with eosinophilia and systemic symptoms (DRESS)
Sulfonamides, anticonvulsants, allopurinol
What is nodular pruigo?
Skin condition characterised by very itchy firm lumps, associated with atopic eczema; more common in black people
Describe the histology of acute eczema
Inflammatory infiltrate (lymphocytes) in the upper dermis, spongiosis, vesicles
Describe the clinical presentation of fixed drug eruptions
Well demarcated round/ovoid plaques
Can present as eczematous lesions, papules, vesicles or urticaria
Red, painful
Occur on hands, genitalia, lips, occasionally oral mucosa
What occurs in the sensation stage of a type I hypersensitivity (allergy)?
Production of specific IgE by B cells (helped by T cells) in response to initial allergen exposure, residual IgE antibodies bind to circulating mast cells via Fc receptors
Describe the clinical features of photo-induced/photosensitive eczema
Caused by a reaction to UV light so there is usually a well defined edge e.g. cut-off collar
Patients often atopic
Name three patient risk factors for a cutaneous drug eruption
Young adults, female, concomitant disease
Describe the clinical features of adult eczema
Generalised dryness and itching, hand eczema may be the primary manifestation
How would you manage moderate eczema?
Moderate topical steroid e.g. betamethasone valerate 0.025%, if face affected start with mild steroid
Where do the majority of venous ulcers tend to occur?
Gaiter area
Why is vitamin B2 important?
Essential co-factor in numerous metabolic reactions
Describe the pathophysiology of phototoxic drug reactions
Drug metabolites interact with UV light (usually triggered by UVA) → free radical release → direct tissue or cell injury → severe rash
Name three drugs associated with drug-induced bullous pemphigoid
ACE inhibitors, penicillin, furosemide
What is small plaque psoriasis?
Plaques <3 cm, often late set of onset
When is phototherapy indicated in psoriasis?
More severe or widespread disease, first line for guttate psoriasis
Which patient group are dermatofibromas more common in?
Immunosuppressed patients
What is eczema herpeticum?
Disseminated viral infection (herpes simplex) characterised by monomorphic punched-out lesions; most commonly seen as a complication of atopic eczema
Describe the pathophysiology of contact allergic dermatitis
Type IV hypersensitivity (T cell) reaction to external antigen e.g. nickel, chemicals, topical therapies, plants
Name a drug which can trigger linear IgA disease
Vancomycin
Describe the clinical presentation of vitamin K deficiency
Bleeding tendency, seen in the skin as purpura and easy bruising
Which patients with psoriasis should use emollients?
Should be used by all patients
What is drug reaction with eosinophilia and systemic symptoms (DRESS)?
Widespread erythema, facial oedema, fever, lymphadenopathy and hepatosplenomegaly which usually starts 2-6 weeks after initial exposure
Name two endocrine disorders which predispose to acne
PCOS, hyperandrogenism
How would you investigate vitamin K deficiency?
Measure coagulation and serum vitamin K
Which physical findings are associated with phototoxicity caused by quinine, thiazides, demeclocycline?
Exaggerated sunburn
How would you define acne that consists of numerous papules, pustules, severe atrophic scarring, cysts, nodules?
Severe
What is rosacea?
Chronic inflammatory skin disease that may be triggered by a number of factors e.g. alcohol, stress
Which investigation is used to confirm anaphylaxis?
Serum mast cell tryptase level
Describe the clinical presentation of type I hypersensitivity (allergy)
Urticaria, angioedema, wheeze/asthma, anaphylaxis
Describe the clinical presentation of vitamin A deficiency
Keratotic follicular papules on the thighs and upper arms, dry skin
Describe the clinical presentation of rosacea
Recurrent facial flushing followed by erythema with papules and pustules (rash)
Describe the clinical presentation of vitamin B6 deficiency
Dermatitis of face, scalp, neck, shoulders, buttocks and perineum, glossitis
Describe the clinical presentation of biotin deficiency
Hyperkeratosis around hair follicles, bent hairs, inflamed gums, poor wound healing
Fatigue, malaise, muscle and bone pain
Describe the management of severe cystic acne
Commence systemic antibiotic therapy and refer immediately for consideration of systemic isotretinion treatment (roaccutane)
Describe the clinical features of a type III allergic adverse drug reaction
Immune complex mediated reactions - purpura/rash
Describe the pathophysiology of atopic eczema
Defective skin barrier allows access/sensitisation to allergen and promotes colonisation by microorganisms
Name three drug risk factors for a cutaneous drug eruption
Chemistry - β-lactam compounds, NSAIDS, high molecular weight/hepten-forming drugs
Topical route
Higher dose/longer half-life
What is erythrodermic psoriasis?
May or may not be proceeded by another form of psoriasis, acute and chronic forms, may result in systemic illness with temperature dysregulation, electrolyte imbalance, cardiac failure
What causes stasis (varicose) dermatitis?
Physical trauma to skin of the lower legs caused by increased hydrostatic pressure of the blood (venous insufficiency) resulting in extravasion of RBCs
How would you investigate biotin deficiency?
Measure serum biotin
Describe the effect of anaphylaxis on breathing
Bronchospasm (wheeze) with tachypnoea
Describe the effect of anaphylaxis on circulation
Hypotension (+ collapse) and/or tachycardia
Describe the effect of anaphylaxis on the airway
Pharyngeal or laryngeal oedema
What is the third-line treatment for rosacea?
Isotretinoin
What lifestyle advice would you give to a patient with rosacea?
Avoid triggers
Which aspect of the history is very important in diagnosing a type I hypersensitivity (allergy)?
Consistent reaction with every exposure to allergen
Describe the management of lichen planus
Topical steroid + antihistamine
Why does acne occur at puberty?
Increased androgens at puberty which causes hypercornification and can also increase sebum production
Name the most common lichenoid disorder
Lichen planus
Mutations in which gene is associated with severe/early onset atopic eczema?
Mutations in fillagrin gene - involved in skin barrier function
What is the Koebner phenomenon?
Appearance of new skin lesions on previously unaffected skin secondary to trauma; seen in eczema and psoriasis
What is the second-line treatment for rosacea?
Topical therapies + oral antibiotics (doxycycline)
Crusting of an eczema lesion indicates secondary infection by which organism?
Staph. aureus
What causes psoriasis?
Inflammation triggered by environmental factors in genetically susceptible individuals (HLA genes)
Describe the clinical features of a type I allergic adverse drug reaction
Anaphylactic reactions, urticaria
What is chronic plaque psoriasis?
Psoriasis that is treatment resistant
How would you manage mild eczema?
Topical steroid
What is wound bed preparation with reference to a leg ulcer?
Removal of devitalized tissue by debridement, can be autolytic, sharp debridement, biological or surgical
Describe the histology of psoriasis
Thickened epidermis with more keratin in the keratin layer, retention of nuclei in keratinocytes (parakeratosis), accumulation of inflammatory cells, particularly neutrophils, in the upper epidermis (micro-abscesses), elongated rete pegs
What causes lichen simplex?
Physical trauma to skin - scratching
Define a type I allergy
IgE-mediated antibody response to external antigen
Describe the clinical presentation of an exanthematous drug eruption
Widespread symmetrically distributed rash 4-21 days after taking drug
Pruritus and mild fever common
Usually mild and self-limiting but can progress to a severe life-threatening reaction
How would you investigate vitamin A deficiency?
Measure serum vitamin A
Define psoriasis
Common chronic inflammatory dermatosis
When would you consider a challenge test in diagnosis of allergy?
If skin prick test negative but history very convincing
When should you aim to heal simple venous ulcers by?
12 weeks
Name three features which indicate an exanthematous drug eruption may be severe (life-threatening)?
Involvement of mucous membrane and face, fever >38.5℃, facial erythema and oedema
What is acrodermatitis enteropathica?
Autosomal recissive disorder resulting in insufficient zinc absorption
Which patient group is most likely to develop rosacea?
More common in females, age 30-40 years
Why is vitamin A important?
Responsible for epithelial proliferation, keratinsation and development
How would you investigate vitamin B2 deficiency?
Measure the activity coefficient of erythrocyte glutathione reductase
Name a medication sometimes used for asthma in the context of allergy
Mast cell stabilisers (e.g. sodium cromoglycate)
Which physical findings are associated with phototoxicity caused by nalidixic acid, tetracyclines, naproxen, amiodarone?
Increased skin fragility
Which physical findings are associated with phototoxicity caused by psoralens?
Delayed 3-5 days erythema and pigmentation
What are phototoxic cutaneous drug reactions?
Non-immunological skin reaction arising in an individual exposed to enough photo-reactive drug and light of the appropriate wavelength
List some general measures for the management of eczema
Remove potential triggers, avoid irritants, loose cotton clothing, emollients
How would you manage severe eczema?
Potent topical steroid e.g. betamethasone valerate 0.1% on inflamed areas
For more sensitive areas moderate potency e.g. betamethasone valerate 0.025%
Define a chronic leg ulcer
Open lesion between the knee and ankle joint that remains unhealed for at least 4 weeks
How would you investigate underlying arterial disease in a patient presenting with a leg ulcer?
ABPI
Describe the clinical presentation of vitamin B3 deficiency
Dermatitis, delirium, diarrhoea, death
Describe the management of a leg ulcer
Pain control, de-sloughing agent if necessary, 4 layer compression bandaging
Which physical findings are associated with phototoxicity caused by chlorpromazine, amiodarone ?
Immediate prickling with delayed erythema and pigmentation
Name a disease associated with lichen planus
Hepatitis C
Describe the clinical features of nail psoriasis
Pitting, onycholysis, yellowing and ridging
What is guttate psoriasis?
Widespread small plaques most commonly after a streptococcal throat infection (strep throat), seen in patients 15-25, often resolves after several months
What causes the majority of chronic leg ulcers (60-80%)?
Venous blood stasis
Give three examples of immunological cutaneous drug reactions
Drug-induced alopecia, phototoxicity, atrophy due to topical steroids
What is the Auspitz sign?
Bleeding points where surface scale of psoriasis is removed
How would you treat telangiectasia + rhinophyma caused by rosacea?
Laser therapy
What is the first-line treatment for rosacea?
Topical metronidazole
Name two long term complications of rosacea
Rhinophyma (thickening of the skin), telangectasia
What is palmoplantar psoriasis?
Psoriasis involving palms and/or soles with keratoderma and painful fissuring
When would you consider skin prick testing for allergy?
If specific IgE negative but history convincing (suspect false negative)
Which immune cells will be present in drug-induced eczema?
Eosinophils
Where do the majority of arterial ulcers tend to occur?
The foot
Why is vitamin K important?
Essential cofactor for several blood coagulation factors
Describe the pathophysiology of acne
Increased androgens at puberty leads to hypercornification
Pilosebaceous units become plugged with keratin, and then become infected with corynebacterium acnes
Keratin and sebum build up to produce comedones
Rupture of comedones will cause the inflammatory lesions
Name the hypersensitivity reactions associated with drug-induced eczema
Type I or Type IV
What is the first-line treatment for a patient with type I hypersensitivity (allergy) after avoidance?
Anti-histamines
Why is vitamin C important?
Required for many metabolic pathways
Required for structure and function of skin so vital for wound healing
Describe the clinical presentation of acrodermatitis enteropathica
Infants develop diarrhoea, alopecia, dry/brittle hair and perioral, facial and acral dermatitis
What is a dermatofibroma?
Proliferation of fibroblasts induced by reaction to insect bite/minor trauma
Name three drugs associated with acute generalised exanthematous pustulosis drug eruptions
Antibiotics, calcium channel blockers, antimalarials
What are lichenoid disorders?
Conditions characterised by damage to basal epidermis
What is Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)?
Life-threateing mucocutaneous drug reactions that are considered variants of a disease spectrum; they are characterised by varying extents of blistering/epidermal detachment and mucosal ulceration
How would you investigate vitamin B3 deficiency?
Clinical diagnosis - diffifult to measure niacin levels
Describe the clinical presentation of lichen planus
Itchy flat-topped violaceous papules on the flexor surfaces of wrist/forearm, ankles and legs
Oral lesions - lacy white lesions on the inside of the cheek
What is flexural psoriasis?
Psoriasis that affects body folds and genitals in smooth, well-defined patches which are colonised by candida yeasts
How would you manage a patient over 12 with mild-moderate acne which has not improved after 3 months of topical therapy?
Lymecycline OD OR doxycycline OD OR erythromycin/carithromycin BD
Which physical findings are associated with phototoxicity caused by calcium channel blockers?
Exposed telangiectasia
What are fixed drug eruptions?
Well demarcated round/ovoid plaques which recur at the same site each time a drug is taken and resolves with persistent pigmentation when drug stops
Can re-occur at same site on re-exposure to drug
Name two lasting effects of chronic acne on the skin
Atrophic scars, skin hyperpigmentation
Which regions are most commonly affected in infantile eczema?
Primarily involves face, scalp and extensor surfaces of the limbs, nappy area usually spared
What is unstable plaque psoriasis?
The rapid extension of existing or new plaques induced by infection, stress, drugs, or drug withdrawal
Why is vitamin B3 important?
Essential co-factor in numerous metabolic reactions
How can diabetes lead to chronic leg ulcers?
Diabetes impedes the normal stages of wound healing
Why is vitamin B6 important?
Co-enzyme for many processes
What is the most commonly used location for coal tar in the treatment of psoriasis?
Scalp
How would you investigate vitamin C deficiency?
Usually clinical diagnosis
Which patient group is most likely to develop acne?
Age 12-24, family history
What is acne?
Inflammatory condition of the pilosebaceous unit
What causes seborrheic eczema (‘cradle cap’)?
Probably a reaction to babies skin being colonised by natural bacteria
Describe the management of a dermatofibroma
Completely benign - reassure, no excision required
How would you investigate zinc deficiency?
Measure serum zinc
Define eczema
Spongiotic inflammation of the skin resulting in itchy skin lesions - similar clinical and pathological features but different pathogenic mechanisms (i.e. different causes)
What are urticarial drug reactions?
Usually an immediate IgE-mediated (type I) hypersensitivity reaction after rechallenge with drug, commonly β-lactam antibiotics, carbamazepine
Can also be due to a direct release of inflammatory mediators from mast cells on first exposure, commonly aspirin, opiates, NSAIDs, muscle relaxants, vancomycin, quinolones
What is the first line topical therapy for psoriasis?
Vitamin D analogues - calciptriol/calcitriol
Why is vitamin C important?
Essential co-factor in collagen formation e.g. hair, and for bone and teeth health
What are exanthematous drug eruptions?
Most common type of drug eruption involving a type IV reaction most commonly associated with antibiotics (beta-lactams, sulfonamides), NSAIDs, anti-epileptics (carbamazepine, phenytoin), alopurinol and chloramphenicol
Describe the clinical presentation of chronic eczema
Thickening (lichenification), elevated plaques, increased scaling, excoriation, secondary infection
Name two treatment options for psoriasis in secondary care
Phototherapy, immunosuppression/immune modulation
Describe the clinical presentation of biotin deficiency
Rare - usually only seen in malabsorptive states or inadequate parenteral nutrition
Facial dermatitis, glossitis, alopecia
How would you investigate vitamin B6 deficiency?
Measure serum or urinary Vitamin B6
Describe the clinical presentation of acquired zinc deficiency
More common, may be due to increased elimination of zinc secondary to burns or infection
Dermatitic rash of hands and feet mainly
Growth retardation in children
Which regions are most commonly affected in childhood eczema?
Predominantly flexural
Name 4 drugs associated with fixed drug eruptions
Antibiotics (tetrecycline, doxycycline), paracetamol, NSAIDs and carbamazepine
When would skin prick testing be contraindicated in a patient with a cutaneous drug reaction?
Serum sickness reactions (Type III) or for Type IV reactions
Those with severe cutaneous adverse drug reactions
What would you advise a parent of a child with an allergy to do in the event of an acute allergic reaction?
- At first sign of reaction give chlorphenamine
- If allergic reaction does not resolve or gets worse over next 30 mins seek urgent medical help and give prednisolone
- If child becomes blue or collapses give adrenaline IV and call 999
