Dermatology I Flashcards
1. Recognise the signs and symptoms of common dermatological conditions 2. Recognise and describe typical presentations of skin conditions involving the face and the parts of the skin that may be visible during a routine dental appointment 3. Understand and be able to explain the oral relevance of dermatological diseases
What is a macule
Localised area of colour or textural change in skin
What is a papule
Small solid elevation of skin <5mm in diameter
What is a nodule
Solid elevation of skin >5mm in diameter
What could nail abnormalities be associated with
- Skin diseases e.g. lichen planus/ psoriasis
- Systemic disease e.g. Iron deficiency anaemia causes Koilonychia, endocrine abnormalities, respiratory, renal, neurological, genetic, immunological, cardiac, GI, liver disease
What can cause finger clubbing
- IBS (esp. Crohn’s) and Malabsorption
- Liver cirrhosis
- Cyanotic congenital heart disease, Atrioventricular malformation, Subacute infective endocarditis
- Grave’s disease
- Lung cancer
- Asbestosis-mesothelioma
- Chronic lung suppuration e.g. CF, bronchiectasis
- TB
- Can be familial
Which of the following is the most likely cause of clubbing and why:
a. Increased capillary pressure in nail fold
b. Local bacterial infection
c. Obstruction of finger capillaries by megakaryocytes
d. Reduced pO2 in the circulation of the nail folds
e. Venous stasis of the nail fold
C
Because megakaryocytic are typically broken down in the lung - as there is accumulation this suggests there is lung damage and lung damage can cause clubbing as a result of megakaryocyte accumulation
What can cause nail pitting
- Psoriasis
- Lichen planus
- Reiter’s syndrome (inflammatory reaction following infection)
- Incontinentia pigmenti (X-linked disorder causing many abnormalities)
- Alopecia areata (autoimmune hair-loss)
What can cause koilonychia
This is nail spooning and is common in infants and can also be caused by
- Iron deficiency anaemia
- Haemochromatosis
- Raynaud’s phenomenon (vascular ischaemia of peripheral fingers)
- Systemic lupus erythematosus
- Trauma
What are Beau’s lines and what are they caused by
These are nail growth defects in horizontal lines relating to a period of systemic illness and is due to
- Any severe illness disrupting nail growth
- Raynaud’s phenomenon
- Pemphigus vulgaris
- Trauma
What can cause splinter haemorrhages
In the outer 1/3 of the nail it is commonly due to trauma
When distributed through nail it is due to
- Infective endocarditis
- Systemic lupus erythematosus
- Rheumatoid disease
- Peptic ulceration
- Malignancy
- Oral contraceptive therapy
- Pregnancy
- Psoriasis
What is herpetic whitlow
Swelling, reddening and tenderness of the skin of infected fingers due to cutaneous Herpes simplex virus (HSV)
What is herpetic whitlow associated with
Pyrexia and lymphadenopathy ; the pain associated seems large relative to apparent clinical features
How does herpetic whitlow progress
Initially vesicles form which can burst and coalesce and this releases virulence
What is paronychia
Localised superficial irritation of the epidermis bordering nails due to infections, chemical irritation or XS contact with moisture (over hand washing)
Typically inflamed nail beds and erythematous appearance
What causes acute paronychia
Staphylococcus aureus
What causes chronic paronychia
Several micro-organisms; Mixture of yeasts, bacteria
- Candida sp,
- Gram negative bacilli
What are the predisposing factors for cutaneous BCC and SCC
- UV radiation (sun exposure in childhood - sunstroke)
- Skin type I/II (freckles, burn on minimal exposure)
- Ionising radiation
- Burn/ vaccination scars
- Immunosuppression (azothioprine)
- Arsenic
What are the specific predisposing factors for BCC
- M > F and > 40
- Outdoor occupation e.g. farming
- Immunosuppression (esp. transplantation)
- Solar elastosis (degenerative condition of elastic tissue due to sun exposure causing thinning)
- Sites of trauma on the face
- Naevus sebaceus (birthmark with extra oil glands)
- Gorlins syndrome
What is BCC
A locally invasive cancer of epidermal basaloid cells which doesn’t commonly metastasise
Outline the presentation of BCC
- Spontaneous ulcer that fails to heal
- Non-healing asymptomatic lump/sore spot that grows slowly
- May bleed with crust formation
What are nodular BCCs
Those which mainly affect head and neck - pearly papule with a rolled edge, telangiectasia and a central area of depression and or ulceration
What are superficial BCCs
Slowly growing scaly pink patches/plaques which can mimic the appearance of eczema or psoriasis
What is the prognosis of BCCs
They grow slowly and are nonaggressive - if neglected and long standing they behave as rodent ulcers which destroy skin and deep tissues; they rarely metastasise
What are the specific predisposing factors for SCC
- Areas of damaged skin in association with actinic keratosis (scaly dry patches affected by sun) and sun exposed sites (face, neck, forearm and hands)
- M > F and > 55
- Chronic granulomas/ ulcers
- Albinism
- Xeroderma pigments (congenital condition, UV sensitivity)
- Erythema ab igne (repeated exposure of direct heat)
What is SCC
Malignant tumour of keratinocytes on the superficial epidermis which can metastasise - very common on lip
What is a malignant melanoma
Malignant tumour of melanocyte which usually arises in epidermis
What are the risk factors for malignant melanoma
- UV radiation (intense intermittent and short)
- Skin types I and II (red hair, blue eyes, freckles)
- Pre-existing melanocytes lesions
- Multiple banal naevi
- Dysplastic/atypical naevi
- Congenital naevi
- Previous malignant melanoma
- Family history of multiple/atypical naevi/melanomas
Describe the diagnostic features in regards to changes in naves/pigmented lesions which are indicative of malignant melanoma
- Increased size
- Irregular shape
- Varying colour
- Erythema at edge
- Crusting, oozing, bleeding
- Itching
Which one of the following would indicate diagnosis of malignant melanoma:
a. Erythematous halo
b. Regular shape
c. Scaling
d. Uniform pigmentation
e. All of the above
A
What is psoriasis
A chronic, non-infectious, relapsing inflammatory condition due to increased numbers of cycling epidermal cells
Outline the presentation of psoriasis
Well demarcated, red, scaly patches of skin topped by silvery scales, there is also pitting/onycholysis of nails
What is onycholysis
Separation of nail from nail bed
What are the different patterns of presentation for psoriasis
- Plaques
- Guttate
- Flextural
- Localised forms
- Generalised pustular
- Nail involvement
- Erythroderma
What are the precipitating factors for psoriasis
- Koebner phenomenon - trauma induced
- Infection - streptococcal sore throat causing guttate psoriasis
- Drugs: beta blockers, lithium, antimalarials
- Stress
- Sunlight (can improve the condition)
- Alcohol
Describe the presentation of plaque-like psoriasis
- Well defined, disc-shaped plaques
- Elbows, knees, scalp hair margin, behind ears, sacrum
- Red plaques covered in white scales
- If detached they leave bleeding points
- Sometimes pruritic (itchy)
What is psoriatic arthropathy
Joint inflammation which typically precedes psoriasis causing deformation and joint destruction
Where can psoriatic arthropathy occur and what are the different types of arthritis it can cause
- Distal arthritis = interphalangeal joints of hands an feet
- Rheumatoid like arthritis
- Mutilans arthritis - associated with severe arthritis
- Ankylosis spondylitis/ sacroilitis
How can psoriasis be treated
- Corticosteroids
- Retinoids
- Vitamin D
- Immunosuppressants: methotrexate, ciclosporin
- Phototherapy
- Biological therapy with monoclonal antibodies
What are the dental aspects of psoriasis
- Associated with geographic tongue and areas of erythema on the dorsum of tongue
- Drug induced gingival hyperplasia (cyclosporin)
- Drug induced oral ulceration (methotrexate)
- Destructive TMJ disease
What is eczema and what is it characterised by
A pattern of non-infective inflammatory cutaneous response characterised by
- Spongiosis (epidermal oedema) in acute stage
- Lichenification (thickening of prickle cell later and hyperkeratosis) in chronic stage - this happens following scratching
What are the endogenous causes of eczema
- Atopic
- Seborrhoeic (affects areas that tend to be greasier)
- Discoid (well-defined, coin shaped)
- Hand and foot
- Asteatotic (pruritic dermatitis)
- Venous (stasis, gravitational) typically in lower limbs and ankles in the elderly
- Lichen simplex
What is atopic eczema
Classically affects the face, knee and elbow flexures and is characterised by an itch scratch cycle which causes lichenification that worsens the eczema and prevents healing
It increases propensity for injection e.g. Eczema herpeticum (infection with herpes)
- 12-15% of children are infects and 2/3 have familial link
- remission occurs in 75% by the age of 15 years
What is atopy
The genetic tendency to develop allergic diseases e.g.
- Eczema
- Asthma
- Hay fever
- Urticaria
- Dermographism
This is associated with high serum IgE levels (allergy immunoglobulin)
What are the exogenous causes of eczema
- Contact irritant
- Contact allergic
- Infective
What is contact dermatitis
It is precipitated by exogenous agents
- if it is allergic it is caused by type IV hypersensitivity
- it may be irritant through damaged skin barriers
- hands and face are most commonly involved
- nickel sensitivity is the most common
What is seborrhoeic dermatitis
It is a red and scaly each which can have erudition and crusting when severe and typically affects the face, side of nose and neck
Which type of patient is susceptible to seborrhoeic dermatitis
Immunosupressed patients e.g. those with HIV as it is associated with yeast P. ovale infection
How is seborrhoeic dermatitis treated
With topical combinations antifungals with a weak corticosteroid
How is eczema treated
- by identifying aetiology
- treating secondary infection
- emollients and soap substitutes (increases eczema risk)
- topical corticosteroids
- immunosupressants
What are the dental aspects of eczema
- Association with atrophy
- Perioral dermatitis = superficial skin infection
- Exfoliative chelitis = lip eczema
- Oral allergy syndrome = antigens recognised by defences causing a burning sensation and swelling
