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