Dermatology

Question 1

Erysipelas vs cellulitis

Answer 1

Cellulitis = deep subcutaneous tissue
Erysipelas = acute superficial form of cellulitis and involves the dermis & upper subcutaneous tissue

Question 2

Cellulitis common organisms

Answer 2

Streptococcus pyogenes & staphylococcus aureus

Question 3

Cellulitis management

Answer 3

Antibiotics (flucloxacillin/benzylpenicillin)
Supportive care - rest, leg elevation, sterile dressings & analgesia

Question 4

Cellulitis complications

Answer 4

Local necrosis, abscess & septicaemia

Question 5

Impetigo

Answer 5

Common superficial bacterial infection of the skin, two main forms are non-bullous and bullous (bullae are fluid filled lesions which are usually more than 5mm in diameter)
Non-bullous impetigo - staphylococcus aureus, streptococcus pyogenes
Bullous impetigo - staphylococcus aureus

Question 6

Impetigo presentations

Answer 6

Non-bullous impetigo presents with thin walled vesicles or pustules which release exudate forming a golden brown crust
-May be mildly itchy but mainly asymptomatic
-Area around mouth and nose is most commonly affected
Bullous impetigo - flaccid fluid filled vesicles & blisters which can persist for 2-3 days, these blisters rupture leaving a thin flat yellow/brown crust
-Most often occur on flexures, face, trunk, limbs
-Systemic features may occur if large areas of skin are affected

Question 7

Impetigo management

Answer 7

Advise person on hygiene measures to aid healing, children & adults to stay away from school/work until the lesions are dry & scabbed over or, if lesions are still crusted/weeping for 48 hours, after abx has started
Non-bullous infection = topical hydrogen peroxide for five days or topical abx
More extensive, severe or bullous infection may require oral abx for 5 days

Question 8

Impetigo complications

Answer 8

Glomerulonephritis & cellulitis

Question 9

Scabies

Answer 9

Intensely itchy skin infestation caused by human parasite Sarcoptes
Classical (typical) scabies - infestation with a low number of mites
Worse at night
Due to a delayed type IV hypersensitivity reaction to the mite & mite products
Crusted scabies is a hyperinfestation with thousands/mites present in exfoliating scales of skin
Erythematous papules disseminated in a characteristic distribution on the periumbilical area, waist, genitalia, breasts, buttocks, axillary folds, fingers, wrists & extensor aspects of the limbs

Question 10

Scabies risk factors

Answer 10

Close contact with an infected person
High levels of poverty & social deprivation
Crowded living conditions
Institutionalisation

Question 11

Scabies diagnosis & management

Answer 11

Skin scraping microscopy can be used to confirm the diagnosis
Management (itching can continue for up to four weeks after successful treatment)
Treat the affected person & all close contacts with a topical insecticide (permethrin 5% cream)
Bedding, clothing and towels should be decontaminated by washing at a high temperature (60 degrees) & drying in a hot dryer or dry cleaning or sealing in a plastic bag for at least 72 hours

Question 12

Chickenpox

Answer 12

Acute infectious disease, predominantly occurring in childhood
Caused by varicella-zoster virus and is characterised by a vesicular rash & often fever + malaise
Transmission is via droplet spread/personal contact with an incubation of 1-3 weeks
Infectious from 24 hours before the rash appears until the vesicles are dry/have crusted over, usually about 5 days after the onset of the rash

Question 13

Chickenpox management

Answer 13

Usually a self-limiting disease
Anti-viral treatment can be considered for an immunocompetent adult or adolescent who presents within 24 hours of rash onset
Treatment of symptoms - paracetamol, topical calamine, chlorphenamine

Question 14

Oral herpes simplex virus

Answer 14

Mild, self-limiting infection of the lips, cheeks or nose (cold sores) or oropharyngeal mucosa (gingivostomatitis)
HSV-1 is the cause in > 90% of causes
Subclinical and asymptomatic
Symptomatic usually presents in children
Transmitted via direct contact with infected secretions
Cold sores usually resolve within 10-14 days, gingivostomatitis usually resolves within 2-3 weeks
Cold sores - crops of vesicles that rupture, ulcer, crust & heal
Gingivostomatitis - crops of painful vesicles that rupture & form ulcers on the pharyngeal & oral mucosa

Question 15

Oral HSV management

Answer 15

Offering analgesia to treat pain & fever
Consider prescribing an oral antiviral (eg. aciclovir or valaciclovir)
Self-care advice to avoid trigger factors

Question 16

Superficial fungal infections

Answer 16

Common & mild infection of the superficial layers of the skin, nails & hair
Can be severe in immunocompromised individuals
Three main groups
-Dermatophytes (tinea/ringworm), yeasts (candidiasis), moulds (aspergillus)
Presentation varies with the site of infection, usually unilateral & itchy
-Tinea capitis (scalp ringworm) - patches of broken hair, scaling and inflammation
-Candidiasis - white plaques on mucosal areas, erythema with satellite lesions in flexures
Ix - establish correct diagnosis by skin scrapings, hair or nail clippings (for dermatophytes) & skin swabs (yeasts)

Question 17

Superficial fungal infections management

Answer 17

General measures - treat known precipitating factors
Topical antifungal agents (eg. terbinafine cream)
Oral antifungal agents (eg. itraconazole) for severe, widespread or nail infections
Avoid the use of topical steroids
Correct predisposing factors where possible

Question 18

Acne vulgaris

Answer 18

Chronic inflammatory skin condition affecting mainly the face, back and chest
Results from increased production of sebum, trapping of keratin and blockage of the pilosebaceous unit (tiny dimples in the skin that contain the hair follicles & sebaceous glands)
Swelling and inflammation in the pilosebaceous unit
Androgenic hormones increase the production of sebum -> why acne is exacerbated by puberty & improves with anti-androgenic hormonal contraception
Comedones must be present for a diagnosis of acne

Question 19

Acne vulgaris management

Answer 19

Avoid over-cleaning the skin (acne is not caused by poor hygiene)
Use a non-alkaline synthetic detergent cleansing product twice daily on acne-prone skin
Avoid oil-based comedogenic skin care products, make-up & sunscreens + make-up should be removed at the end of the day
Mild to moderate acne - 12 week course of one of the following first-line options to be applied once daily in the evening
-Fixed combination of topical adapalene with topical benzoyl peroxide
Moderate to severe acne - 12 week course of the following first-line options:
-Fixed combination of topical adapalene with topical benzoyl peroxide to be applied once daily in the evening.
Combined oral contraceptives in combination with topical agents can be considered as an alternative to systemic antibiotics in women

Question 20

Atopic eczema

Answer 20

Chronic, itchy, inflammatory skin condition that affects people of all ages, although it presents most frequently in childhood (70-90% of cases occur before 5 years of age, with a high incidence of onset in the first year of life)
Positive FHx of atopy often present
Exacerbating factors - infections, allergens, sweating, heat, occupation & severe stress

Question 21

Atopic eczema management

Answer 21

Stepped approach is recommended
Emollients are the first-line treatments during both acute flares & remissions of the condition
Topical corticosteroids - considered for red, inflamed skin
Lowest potency & amount of topical corticosteroid necessary to control symptoms should be prescribed
SE: stinging sensation when the medicine is applied, inflamed hair follicles, thinning of skin, withdrawal is using > 12 months
Persistent, severe itch or urticaria = 1 month trial of non-sedating antihistamine
Severe itching & affecting sleep = short course of a sedating anti-histamine
Severe, extensive eczema = short course of oral corticosteroids
Infected eczema = abx treatment

Question 22

Urticaria

Answer 22

Superficial swelling of the skin (epidermis and mucous membranes) that results in a red, raised, itchy rash
Angio-oedema = deeper form of urticaria with swelling in the dermis and submucosal/subcutaneous tissues
Classified according to its duration:
-Acute - symptoms last for < 6 weeks
-Chronic - symptoms persist > 6 weeks or longer on a nearly daily basis

Question 23

Urticaria management

Answer 23

Identify and manage the underlying causes/trigger factors of urticaria where possible
-Mild with an identifiable & avoidable cause/trigger - urticaria is likely to be self-limiting without treatment
People with symptoms requiring treatment
-Non-sedating antihistamine (eg. cetirizine, fexofenadine) for up to 6 weeks
-If symptoms are severe, give a short course of oral corticosteroid (eg. prednisolone for up to 7 days) in addition to antihistamine

Question 24

Psoriasis

Answer 24

Systemic, immune-mediated, inflammatory skin disease which typically has a chronic relapsing-remitting course & may have nail and joint involvement
Chronic plaque psoriasis is most common form
Other types include guttate, seborrhoeic, flexural, pustular and erythrodermic
Precipitating factors include trauma, infection, drugs, stress and alcohol

Question 25

Psoriasis management

Answer 25

Lifestyle advice - weight loss, smoking cessation & alcohol reduction
Management of associated stress, distress, anxiety and/or depression
Treatment with topical preparations
Emollients
Topical therapies - corticosteroids, vitamin D analogues, coal tar, short-contact dithranol (large plaque psoriasis)
Phototherapy for extensive disease

Question 26

Basal cell carcinoma

Answer 26

Slow-growing, locally invasive malignant tumour of the epidermal keratinocytes normally in older individuals, only rarely metastasises
Risk factors: UV exposure, history of frequent/severe sunburn in childhood, increasing age, male sex, immunosuppression
Typical features - an ulcer with a raised rolled edge, prominent fine blood vessels around a lesion, or a nodule on the skin

Question 27

Basal cell carcinoma management

Answer 27

Consider routine referral for people if they have a skin lesion that raises the suspicion of a basal cell carcinoma (only 2WW if there is particular concern)
Confirmation of diagnosis is generally made by excision biopsy
Management
Surgery - surgical excision (lowest recurrence rate)
Non-surgical interventions - radiotherapy

Question 28

Squamous cell carcinoma

Answer 28

Locally invasive malignant tumour of the epidermal keratinocytes or its appendages, which has the potential to metastasise
Risk factors - excessive UV exposure, pre-malignant skin conditions, chronic inflammation, immunosuppression & genetic predisposition
Usually seen as a raised lesion on the skin, nodular keratinising/crusted tumour that may ulcerate without evidence of keratinisation

Question 29

Squamous cell carcinoma management

Answer 29

Confirmation of diagnosis is generally made by excision biopsy
Consider a 2WW referral for people with a skin lesion that raises the suspicion of SCC
Management
-Wide local excision
-Mohn’s micrographic surgery - excision of a skin lesion is carried out in stages and checked histologically
-Non-surgical procedures - radiotherapy, curretage & cautery, cryotherapy & imiquimod cream