Dermatology 2

Question 1

What is pre tibial myxoedema?

Answer 1

Pretibial myxoedema
symmetrical, erythematous lesions seen in Graves’ disease
shiny, orange peel skin

Question 2

Different shin lesions?

Answer 2

Erythema nodosum
symmetrical, erythematous, tender, nodules which heal without scarring
most common causes are streptococcal infections, sarcoidosis, inflammatory bowel disease and drugs (penicillins, sulphonamides, oral contraceptive pill)

Pretibial myxoedema
symmetrical, erythematous lesions seen in Graves’ disease
shiny, orange peel skin

Pyoderma gangrenosum
initially small red papule
later deep, red, necrotic ulcers with a violaceous border
idiopathic in 50%, may also be seen in inflammatory bowel disease, connective tissue disorders and myeloproliferative disorders

Necrobiosis lipoidica diabeticorum
shiny, painless areas of yellow/red skin typically on the shin of diabetics
often associated with telangiectasia

Question 3

what inheritance pattern is hereditary hemorrhagic telangiectasia?

Answer 3

autosomal dominant pattern of inheritance and age-related penetrance

Question 4

what is hereditary haemorrhage telangiectasia?

Answer 4

Also known as Osler-Weber-Rendu syndrome, hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant condition characterised by (as the name suggests) multiple telangiectasia over the skin and mucous membranes. Twenty percent of cases occur spontaneously without prior family history.

Question 5

Diagnostic features of hereditary haemorrhage telangiectasia?

Answer 5

There are 4 main diagnostic criteria. If the patient has 2 then they are said to have a possible diagnosis of HHT. If they meet 3 or more of the criteria they are said to have a definite diagnosis of HHT:
epistaxis : spontaneous, recurrent nosebleeds
telangiectases: multiple at characteristic sites (lips, oral cavity, fingers, nose)
visceral lesions: for example gastrointestinal telangiectasia (with or without bleeding), pulmonary arteriovenous malformations (AVM), hepatic AVM, cerebral AVM, spinal AVM
family history: a first-degree relative with HHT

Question 6

what is pellagra?

Answer 6

Pellagra is a caused by nicotinic acid (niacin, B3) deficiency. The classical features are the 3 D’s - dermatitis, diarrhoea and dementia.

Pellagra may occur as a consequence of isoniazid therapy (isoniazid inhibits the conversion of tryptophan to niacin) and it is more common in alcoholics.

Question 7

Features of Pellagra?

Answer 7

dermatitis (brown scaly rash on sun-exposed sites - termed Casal’s necklace if around neck)
diarrhoea
dementia, depression
death if not treated

Question 8

Lichen planus vs lichen sclerosus?

Answer 8

planus: purple, pruritic, papular, polygonal rash on flexor surfaces. Wickham’s striae over surface. Oral involvement common
sclerosus: itchy white spots typically seen on the vulva of elderly women

Question 9

treatment of lichen planus?

Answer 9

potent topical steroids are the mainstay of treatment
benzydamine mouthwash or spray is recommended for oral lichen planus
extensive lichen planus may require oral steroids or immunosuppression

Question 10

What is bullous pemphigoid?

Answer 10

Bullous pemphigoid is an autoimmune condition causing sub-epidermal blistering of the skin. This is secondary to the development of antibodies against hemidesmosomal proteins BP180 and BP230.

Question 11

Features of Bullous pemphigoid?

Answer 11

itchy, tense blisters typically around flexures
the blisters usually heal without scarring
there is stereotypically no mucosal involvement (i.e. the mouth is spared)
in reality around 10-50% of patients have a degree of mucosal involvement. It would, however, be unusual for an exam question to mention mucosal involvement as it is seen as a classic differentiating feature between pemphigoid and pemphigus.

Question 12

What will a skin biopsy in Bullous pemphigoid show?

Answer 12

immunofluorescence shows IgG and C3 at the dermoepidermal junction

Question 13

what is necrobiosis lipoidica diabeticorum?

Answer 13

Necrobiosis lipoidica diabeticorum. This condition is a rare skin disorder of unclear aetiology, often associated with diabetes mellitus. It typically presents as shiny, atrophic, yellow-brown plaques on the shins with telangiectasia and occasional ulceration. The patient’s age, the location of the lesion and its description fit this diagnosis.

Question 13

Management of Bullous phemphigoid?

Answer 13

referral to a dermatologist for biopsy and confirmation of diagnosis
oral corticosteroids are the mainstay of treatment
topical corticosteroids, immunosuppressants and antibiotics are also used

Question 14

treatment for rosacea with predominant erythema/flushing?

Answer 14

topical brimonidine gel may be considered for patients with predominant flushing but limited telangiectasia
brimonidine is a topical alpha-adrenergic agonist
this can be used on an ‘as required basis’ to temporarily reduce redness
it typically reduces redness within 30 minutes, reaching peak action at 3-6 hours, after which the redness returns to the baseline

Question 15

treatment for rosacea with papules/pustules?

Answer 15

mild-to-moderate papules and/or pustules
topical ivermectin is first-line
alternatives include: topical metronidazole or topical azelaic acid
moderate-to-severe papules and/or pustules
combination of topical ivermectin + oral doxycycline

Question 16

treatment of acne in pregnancy?

Answer 16

use oral erythromycin if treatment needed

Question 17

Pregnant lady develops rash - when should steroids be used?

Answer 17

Presence of blisters
Pemphigoid gestationis is a blistering rash which develops around the umbilicus before spreading to other areas and, in many cases will be treated with oral steroids. Atopic eruption and polymorphic eruption of pregnancy are non-blistering rashes which would only be treated with oral steroids if symptoms are severe or if topical treatments had failed. Blistering is specific to pemphigoid gestationis which can have complications such as secondary infection and premature delivery.

Question 18

what conditions are associated with seborrhoea dermatitis?

Answer 18

HIV
Parkinson’s disease

Question 19

Features of seborrhoeic dermatitis?

Answer 19

eczematous lesions on the sebum-rich areas: scalp (may cause dandruff), periorbital, auricular and nasolabial folds
otitis externa and blepharitis may develop

Question 20

management of scalp seborrhoeic dermatitis?

Answer 20

the first-line treatment is ketoconazole 2% shampoo
over the counter preparations containing zinc pyrithione (‘Head & Shoulders’) and tar (‘Neutrogena T/Gel’) may be used if ketoconazole is not appropriate or acceptable to the person
selenium sulphide and topical corticosteroid may also be useful

Question 21

Management of face and body seborrhoeic dermatitis?

Answer 21

topical antifungals: e.g. ketoconazole
topical steroids: best used for short periods
difficult to treat - recurrences are common

Question 22

Features of zinc deficiency?

Answer 22

Features
acrodermatitis: red, crusted lesions
acral distribution
peri-orificial
perianal
alopecia
short stature
hypogonadism
hepatosplenomegaly
geophagia (ingesting clay/soil)
cognitive impairment

Question 23

What is acrodermatitis enteropathica?

Answer 23

Acrodermatitis enteropathica is a recessively inherited partial defect in intestinal zinc absorption.

Question 24

what does Dermatitis in acral, peri-orificial and perianal distribution suggest?

Answer 24

zinc deficiency

Question 25

what is pityriasis versicolor cased by? what are the features? what is the management ?

Answer 25

caused by a superficial cutaneous fungal infection caused by Malassezia furfur Features most commonly affects trunk patches may be hypopigmented, pink or brown (hence versicolor). May be more noticeable following a suntan scale is common mild pruritus Management topical antifungal. NICE advises ketoconazole shampoo as this is more cost effective for large areas if failure to respond to topical treatment then consider alternative diagnoses (e.g. send scrapings to confirm the diagnosis) + oral itraconazole

Question 26

what is Pompholyx? what are the features? How is it. managed?

Answer 26

Pompholyx is a type of eczema which affects both the hands (cheiropompholyx) and the feet (pedopompholyx). It is also known as dyshidrotic eczema. Pompholyx eczema may be precipitated by humidity (e.g. sweating) and high temperatures. Features small blisters on the palms and soles pruritic often intensely itchy sometimes burning sensation once blisters burst skin may become dry and crack Management cool compresses emollients topical steroids

Question 27

causes of erythroderma?

Answer 27

eczema psoriasis drugs e.g. gold lymphomas, leukaemias idiopathic

Question 28

what is Tinea and what are the different types?

Answer 28

Tinea is a term given to dermatophyte fungal infections. Three main types of infection are described depending on what part of the body is infected tinea capitis - scalp tinea corporis - trunk, legs or arms tinea pedis - feet

Question 30

What is Tinea capitis commonly known as?

Answer 30

Scalp ringworm

Question 31

In which population is Tinea capitis mainly seen?

Answer 31

Children

Question 32

What serious condition can form if Tinea capitis is untreated?

Answer 32

Kerion ## Footnote a raised, pustular, spongy/boggy mass

Question 33

What is the most common cause of Tinea capitis in the UK and the USA?

Answer 33

Trichophyton tonsurans may also be caused by Microsporum canis acquired from cats or dog

Question 34

What diagnostic method shows green fluorescence for lesions caused by Microsporum canis?

Answer 34

Wood's lamp

Question 35

What is the most useful investigation for diagnosing Tinea capitis?

Answer 35

Scalp scrapings

Question 36

According to NICE guidelines, what is the oral antifungal treatment for Trichophyton tonsurans infections?

Answer 36

Terbinafine

Question 37

Which oral antifungal is recommended for Microsporum infections?

Answer 37

Griseofulvin

Question 38

What topical treatment should be given for the first two weeks to reduce transmission of Tinea capitis?

Answer 38

Ketoconazole shampoo

Question 39

what causes tinea corporis?

Answer 39

ringworm causes include Trichophyton rubrum and Trichophyton verrucosum (e.g. From contact with cattle)

Question 40

what is the management of ringworm?

Answer 40

oral fluconazole

Question 41

what is Tinea pedis?

Answer 41

Tinea pedis (athlete's foot) characterised by itchy, peeling skin between the toes common in adolescence

Question 42

What factors may exacerbate psoriasis?

Answer 42

trauma alcohol drugs: beta blockers, lithium, antimalarials (chloroquine and hydroxychloroquine), NSAIDs and ACE inhibitors, infliximab withdrawal of systemic steroids Streptococcal infection may trigger guttate psoriasis.

Question 43

Causes of pyoderma gangrenosum?

Answer 43

idiopathic in 50% inflammatory bowel disease in 10-15% ulcerative colitis Crohn's rheumatological rheumatoid arthritis SLE haematological myeloproliferative disorders lymphoma myeloid leukaemias monoclonal gammopathy (IgA) granulomatosis with polyangiitis primary biliary cirrhosis

Question 44

what is pyoderma gangrenosum classified as?

Answer 44

pyoderma gangrenosum is classified as a neutrophilic dermatosis neutrophilic dermatoses are skin conditions characterised by dense infiltration of neutrophils in the affected tissue and this is often seen on biopsy

Question 45

Features of pyoderma gangrenosum?

Answer 45

typically on the lower limb often at sit of minor injury usually starts quite suddenly - as a small pustule red bump or blood blister later features - this skin breaks down rsulting in an ulcer - often painful The edge of the ulcer is ofted described as purple violaceous and undermined the ulcer itself is deep and necrotic fever and myalgia

Question 46

Management of pyoderma?

Answer 46

oral steroids first line other immunosuppressive therapy, for example, ciclosporin and infliximab, have a role in difficult cases

Question 47

what is hyperhidrosis?

Answer 47

Hyperhidrosis describes the excessive production of sweat.

Question 48

what is the management of hyperhidrosis?

Answer 48

topical aluminium chloride preparations are first-line. Main side effect is skin irritation iontophoresis: particularly useful for patients with palmar, plantar and axillary hyperhidrosis botulinum toxin: currently licensed for axillary symptoms surgery: e.g. Endoscopic transthoracic sympathectomy. Patients should be made aware of the risk of compensatory sweating

Question 49

what causes porphyria cutanea tarda?

Answer 49

Porphyria cutanea tarda is the most common hepatic porphyria. It is due to an inherited defect in uroporphyrinogen decarboxylase or caused by hepatocyte damage e.g. alcohol, hepatitis C, oestrogen.

Question 50

Features of Porphyria cutanea tarda?

Answer 50

classically presents with photosensitive rash with blistering and skin fragility on the face and dorsal aspect of hands (most common feature) hypertrichosis hyperpigmentation

Question 51

Investigations for Porphyria cutanea tarda?

Answer 51

urine: elevated uroporphyrinogen and pink fluorescence of urine under Wood's lamp serum iron ferritin level is used to guide therapy

Question 52

Management of Porphyria cutanea tarda?

Answer 52

chloroquine venesection preferred if iron ferritin is above 600 ng/ml

Question 53

what is Bullous pemphigoid?

Answer 53

Bullous pemphigoid is an autoimmune condition causing sub-epidermal blistering of the skin.

Question 54

what antibodies are seen in Bullous pemphigoid?

Answer 54

antibodies against hemidesmosomal proteins BP180 and BP230.

Question 55

How does Bullous Pemphigoid present?

Answer 55

More common in elderly patients itchy, tense blisters typically around flexures the blisters usually heal without scarring there is stereotypically no mucosal involvement (i.e. the mouth is spared) in reality around 10-50% of patients have a degree of mucosal involvement. It would, however, be unusual for an exam question to mention mucosal involvement as it is seen as a classic differentiating feature between pemphigoid and pemphigus.

Question 56

what does a skin biopsy show in bullous pemphigoid?

Answer 56

immunofluorescence shows IgG and C3 at the dermoepidermal junction

Question 57

Management of Bullous pemphigoid?

Answer 57

referral to a dermatologist for biopsy and confirmation of diagnosis oral corticosteroids are the mainstay of treatment topical corticosteroids, immunosuppressants and antibiotics are also used

Question 58

How to manage fungal nail infecition?

Answer 58

no treatment if asymptomatic f limited involvement (≤50% nail affected, ≤ 2 nails affected, more superficial white onychomycosis): topical treatment with amorolfine 5% nail lacquer; 6 months for fingernails and 9 - 12 months for toenails if more extensive involvement due to a dermatophyte infection: oral terbinafine is currently recommended first-line; 6 weeks - 3 months therapy is needed for fingernail infections whilst toenails should be treated for 3 - 6 months if more extensive involvement due to a Candida infection: oral itraconazole is recommended first-line; 'pulsed' weekly therapy is recommended

Question 59

Management of facial Hirsutism in PCOS patients?

Answer 59

facial hirsutism: topical eflornithine - contraindicated in pregnancy and breast-feeding

Question 60

What is systemic mastocytosis associated with?

Answer 60

Increased histamine production and increased gastric acid secretion ## Footnote This predisposes patients to gastritis and peptic ulcers.

Question 61

What predisposes patients with systemic mastocytosis to gastritis and peptic ulcers?

Answer 61

Increased histamine production and increased gastric acid secretion.

Question 62

What is urticaria pigmentosa?

Answer 62

A rash characterised by innumerable reddish-brown papules that undergo an urticarial reaction on irritation. ## Footnote This reaction upon irritation is known as Darier's sign.

Question 63

What is Darier's sign?

Answer 63

The urticarial reaction that occurs upon irritation of urticaria pigmentosa.

Question 64

In which age group is urticaria pigmentosa typically seen?

Answer 64

Childhood forms of the disease.

Question 65

Can urticaria pigmentosa occur in adults?

Answer 65

Yes, it can also occur in adults and tends to persist for longer.

Question 66

What laboratory findings are associated with systemic mastocytosis?

Answer 66

Raised serum tryptase and urinary histamine levels.