Integrated Specialties D - Dermatology revision assessment - very difficult Flashcards
A 33 year-old female lab worker with a long history of atopic dermatitis has experienced gradual worsening over the past few years since the birth of her two children. Her hands are particularly bad, although she can identifiy no particular triggers. There is no improvement when on holiday from work. Which one of the following investigations is likely to be most useful? Select one:: * a. Viral swab * b. Patch test * c. Skin prick test * d. RAST test * e. Skin scraping
* The most useful investigation is likely to be a patch test for delayed hypersensitivity. * Infections, (particularly viral) would tend to present more acutely and be asymmetrical. * RAST and skin prick test are indicated when type 1 hypersensitivity is suspected. * Remember: Investigations must be used appropriately to be useful. The correct answer is: Patch test - contact allergy dermatitis
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Previous CVA and history of smoking both associated with arterial disease. Same side fractures/orthopaedic surgery, ankle swelling, previous DVT, varicose veins, haemosiderin staining and lipodermatosclerosis all suggestive of underlying venous cause, ABP1 tends to be 0.8-1.3 in venous ulcers but is lower or significantly raised (due to calcification) in arterial ulceration. The correct answers are: Previous fractured NOF, Haemosiderin staining, ABPI in range 0.8-1.0
An 82 year-old Asian man is due to receive cryotherapy to an actinic keratosis on his cheek. Prior to consenting to treatment which of the following should you explain to the patient? Select one or more: * a. This is a safe treatment with no recognised side effects * b. Inflammation & blistering are common following cryotherapy * c. This is a cutaneous treatment with no risk to underlying structures * d. Cryotherapy should be used with caution in darker skin types
* Most common SE seen in cryotherapy is inflammation and blistering. Melanocytes are particularly sensitive to cryotherapy so use on darker skins may result in depigmentation. Depth of freeze depends on the duration so in areas of thinner skin (eg dorsal hand) there is a risk to underlying structures such as extensor tendons with prolonged freezing. * The correct answers are: Cryotherapy should be used with caution in darker skin types * Inflammation and blistering are common following cryotherapy
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Emollient, soap substitutes and steroids are all indicated in this case Antibiotics prophylactically should not be encouraged as this leads to resistance. Hand sanitiser gel is likely to further aggravate her dermatitis
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Skin scrapings are indicated only if fungal infection is suspected Autoantibodies may not be positive in purely cutaneous lupus Plasma viscosity may be elevated but this is a non-specific test The patient may be photosensitive but a positive test will not be specific for lupus The correct answer is: Biopsy for H + E, Immunofluorescence
On the biopsy sample from your patient with tense bullae, a further investigation has been performed known as immunofluorescence. What does this image show?
This image shows the results of the immunoflourescence - linear IgG deposition at dermoepidermal junction
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The correct answer is: Daily oral Acitretin (a retinoid)
A 7 year-old girl has developed localised flaccid blisters and erosions on one forearm. She is systemically well and on no medication. There is apparently an outbreak of impetigo in her primary school. You suspect the bullous variant of impetigo. Which one of the following statements is true? * a. Potent topical steroids are indicated for blistered sites * b. A staphylococcal exotoxin is produced which causes splitting at the dermo- epidermal junction * c. This is localised variant of staphylococcal scalded skin syndrome * d. Blood cultures should be taken * e. This is more commonly seen in adults
This is localised variant of staphylococcal scalded skin syndrome
A 28 year-old male with lifelong atopic eczema is 2 weeks into his first course of UVB phototherapy for a stubborn flare. You are asked to see him due to the development of multiple monomorphic eroded papules/ vesicles which have developed over the last few days. Viral swabs are positive for herpes simplex. The rash consists of papules/vesicles which are generalised over the face, trunk and upper limbs and have developed over the last few days. This infective complication is known as what?
Eczema heperticum This is a recognised infective complication in patients with excema and may be triggered by UVB which causes local skin immunosuppression allowing the virus to flourish.
A 65 year-old man with no previous history of skin problems has developed an itchy rash mainly on his legs. On examination you see well-defined circular areas of erythema measuring about 2 cm in diameter. Scale is evident across the surface with some excoriation present. Which feature would suggest most strongly that this is an epidermal process? * a. Scale * b. Well-defined lesions * c. Excorations * d. Erythema * e. Affecting legs
Scale indicates epidermal involvement Erythema, clearly defined border, excoriations and affecting particular sites are not specific to epidermal lesions. Clues to the histological site of the pathological process can be obtained from careful examination.
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Elliptical excision generally results in a scar which is 3x as long as the lesion to be removed. - T Keloid scarring is more common on the pre-sternal area, upper back, scapulae and upper outer arms - T INR typically checked 2-3 days before procedure to ensure level is below 3. - T Shave excision or curettage - Full excision is indicated to allow complete histological assessment of the lesion if malignancy is suspected. Adrenaline is contra-indicated in extremities, e.g. fingers, toes and male genitalia, but not in patients with pacemakers
A 34 year-old man has had dry skin since childhood and would like to know the underlying cause. Which investigation would be most useful in establishing if this is due to atopic eczema? Select one: * a. Diagnostic biopsy * b. Genetic sequencing * c. Total IgE level * d. FBC looking for eosinophilia * e. Indirect immunoflorescence
Total IgE level - Atopic individuals have a genetic predisposition to producing high levels of IgE in response to environmental allergens. Eosinophilia may be seen, but is also found in other conditions e.g. contact allergy, drug reactions, Diagnostic biopsy may show dermatitis but would not help differentiate what the cause of the dermatitis is . Indirect immunofluorescence tests for autoantibodies in autoimmune conditions
A 28 year-old female presents with a facial rash. On examination you see a combination of papules and comedones over both cheeks. The presence of……………. favours a diagnosis of acne rather than Rosacea?
Comedomes
A 32 year-old man has an itchy, scaly rash extending from the toes proximally over the dorsal right foot. No other sites are affected. This rash is likely to be due to an external cause because of the …………. distribution.
Asymmetry suggests infection or other external cause (e.g contact allergy). Endogenous inflammatory conditions are usually symmetrical in distribution.
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The correct answers are: Lesions typically last less than 24 hours, Phototherapy can be an effective treatment Antihistamines are more effective if taken regularly to prevent lesions developing. Food allergy is more likely to cause an urticarial eruption, lasting less than 6 weeks. In most cases of chronic urticarial the cause is not identified. An Epipen is only considered if angioedema and breathing difficulty is a feature.
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The itch can persist for a week or so even after successful treatment. Symptomatic treatment (eg topical anti-pruritic) is indicated The correct answer is: The itch often takes a little while to settle even after successful treatment
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Although BCCs are associated with an excellent prognosis they can be locally invasive and destructive so in this site they should be treated. The optimal method would be Mohs micrographic surgery which ensures complete removal of the lesion with maximum conservation of normal tissue. The correct answer is: Mohs micrographic surgery is the best treatment option for this lesion and site
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The image shows a sub-epidermal split that indicates Bullous Pemphigoid. In Bullous pemphigus the split is within the granular layer and produces superficial blisters that burst easily. In Bullous impetigo the split is within the granular layer and produces superficial blistering and erosion. Dermatitis herpetiformis, associated with coeliac disease, manifests as small itchy vesicles often on extensor sites. Acute contact dermititis - widespread spongiosis (fluid accumulation) within the epidermis which can lead to blistering.
