Dermatology Flashcards
Where are Langerhan Cells usually found?
In the Stratum Basalis
Where and what do the Merkels cells do?
Base of epidermis
Gentle - localised pressure
Where and what do the Meissner corpuscles do?
Immediately below Epidermis
- heavy on palms and lips
Light touch
Where and what do Ruffini’s corpuscles do?
In the dermis
Deep pressure and stretching
Where and what do Pacinian corpuscles do?
Deep dermis
Deep touch and proprioception
What is a Macule:
Flattened area of abnormality.
What is a papule:
Raised area of skin
What is a Pustule:
Raised, full of pus
What is a plaque:
Raised large area of skin. like a papule but much larger. can often be crusted.
What is a Vesicle:
Small blister formation
What is a bulla:
Large blister formation
What is erythematous:
Red, inflamed
What must be present for the diagnosis of acne vulgaris?
At least 3/4 of the following:
- Papules
- Pustules
- Erythema
- Comedones
What is the gene that is thought to be associated with atopic eczema and may be associated with other atopic pathologies such as asthma?
Filaggrin
- chromosome 1
What is it called when the herpes virus infects someone (usually infant) with eczema leading to wide spread papules which are itchy and sore?
Eczema Herpeticum
What is is called when there is direct damage to the skin via a substance, involving no immune reaction? i.e. it has a direct noxious effect?
Irritant contact dermatitis
If a female comes into the clinic with acne, which much worse during particularly times of the menstrual cycle and is overweight, what should you be thinking as a possible cause?
Polycystic ovarian syndrome
What are the main types of acne?
Vulgaris
Fulminans
- emergancy
Steroid
Inversus
Rosacea
What is needed to make a diagnosis of acne?
Comedones papules pustules and/ or erythema
What must females be placed on if taking isotretinion A?
Pregnancy prevention program
What infection may be a risk factor for developing psoriasis and what type would someone develop?
Strep infection.
Gluttate
- short lived
What are the major types of psoriasis?
Plaque
Gluttate
Keobner
- occurs in place of trauma
- usually around scars
Inverus
Palmer pustular
What is the genetic susceptibility in eczema?
Filaggrin
- chromosome 1
Outline the pathophysiology of atopic eczema
Type I Hypersensitivity reaction
edema pushes the keratinocytes apart causing pickling.
leads to itching and cracking
Lichenification occurs
What is it called when there is a co- infection of eczema and herpes?
Eczema Herpeticum
What are second line treatments for eczema?
Immunosuppressive
UV
Oral retinoids
Biological agents
What are the main subtypes of eczema?
Atopic
Contact
Seborrhoeic dermatitis
Venous
What is the pathogen in Seborrhoeic dermatitis?
Also what is it commonly known as in babies?
Pityrosporum Ovale
Cradle cap
What is the treatment of seborrhoeic dermatitis?
Ketoconazole shampoo
Antimicrobial face wash
steroid cream
moisturisers
UV
How does UV light increase the risk of skin cancer?
Immunosuppression:
Trans UCA transformed to Cis UCA
Cis UCA switches off immune cells.
Direct cellular damage:
- free radicals
- double stranded DNA break
- mutations in p53
What are some key symptoms of a skin cancer?
Increase in size
Itchiness
Ulceration/ bleeding
What gene is usually damaged in basal cell carcinoma?
PTCH gene
- suppressor protein as mpat of the sonic hedgehog pathway
What’s a type of excisional surgery that can be used on cancerous cells?
Mohs Micrographic surgery
Name two premalignant conditions of squamous cell carcinomas:
Actinic kertatosis
Bowen’s disease
- carcinoma in situ
What measurement is used to work out prognosis of melanoma?
Clinical appearance
histological
- Breslow’s depth
What are the surgical excisions for melanoma?
<1mm = 1cm margin
> 1mm = 2cm margin
List the treatment options for melonoma:
Surgical excision
Immunotherapy
- PDLA-4 = Ipilimumab
Immune check point
- MEK inhibitors
BRAF v600E inhibitors
- Vemurafenib
Imaging for metastasis
assessment of lymph nodes
What the most common pathogens of impetigo?
and what is the treatment?
S. Aureus
S. Pyogenes
**Fusidic acid
What the classification system used for cellulitis?
Enron Classification
Whats the drug choice for OPAT in cellulitis?
Ceftriaxone
What are some common pathogens that are associated with bites?
What is the treatment:
S. aureus
S. Strep
Anaerobics
Pasteurella
Capnocytophaga
- these two are common in cats
treatment:
1st: Co-amoxiclav
2nd: doxycycline + metronidazole
Surgical debridement
Prophylactic treatment:
- rabies
- tetanus
When an IV drug user comes in with an infection, what else should be done out with cultures and antibiotics?
chest x-ray
echocardiogram
What is the bacteria associated with highly virulent and contagious boil formation on the skin?
PVL staphylococcus
PVL is an exotoxin produced by S. Aureus
What the phases of hair growth?
Anagen
- nourishment
Catagen
- follicle detaches
Telogen
- follicle falls out
What is the immune mediated type of hair loss seen? list some types of presentation with it?
and what is a poor prognostic sign?
How is it treated?
Alopecia Areata:
Immune development against hair follicles. associated with other immune conditions such as thyroid disease.
- Localised alopecia areata
- Alopecia totalis
- Alopecia universalis
Treated:
- Clobetasol - topical steroid
- topical immunotherapy
- 5% minoxidil
What the type of hair loss that occurs due to stress?
Telogen effluvium
What is it called when there is a psychological problem of hair pulling?
Trichotillomania
List some skin conditions seen in diabetes:
Necrobiosis Lipoderca
- yellow/ red patches on shins
Diabetic dermopathy
- brown spots on shins
Sceledema
- hardening and thickening of skin
Granuloma Annulare
- small papule rings that join together to form large rings
Type III Aconthosis Nigricans
If there was an islet tumour of the pancreas, what skin disease may you see? and how does it present?
Necrolytic migratory erythema
- blistering rash with scaly plaques
usually around the mouth
If a person had lung cancer, what skin condition may you see?
how does it present and list some other cancers it is associated with:
Erythema Gyratum Repens
Circular, woodgrain pattern
Breast
cervical
G.I
If a person had adenocarcinoma of G.I tract what skin condition might you see?
Type I acanthosis nigricans
In B6 deficiency what skin condition may you see?
Pyridoxine dermatitis
- around lips and mouth
In zinc deficiency, what skin condition may you see?
Acrodermatitis enteropathica
If a person has inflammatory condition such as, Chrons or RA, or even myeloma, what skin condition may they have?
Pyoderma Gangrenosum
In acute erythroderma, what is the pathology and what are the complications?
inflammatory reaction involving nearly the entire skin.
usually due to drug reactions.
complications include:
- infection
- temperature dysfunction
- high output heart failure
significant loss of fluids
What drug may cause venous ulceration?
Nicrorandil
What investigations should be done when someone has a venous ulcer?
What are the scores?
Ankle brachial pressure Index.
<0.8 ratio - occlusion
> 1.1 ratio - calcification
How does cellulitis and impetigo differ?
Impetigo is infection in the superficial levels
- honey crusted with discharge
where as cellulitis is deeper dermis and subcut tissue.
usually presents with fever and deep red rash
What drug may cause Psoriasiform rash?
Beta Blockers
Lithium
Name a drug that commonly causes a fixed rash?
Paracetamol
What cancer is associated with PTCH gene defects?
Basal cell carcinoma
Which type of blistering condition causes the entire epidermis to lift up? and how does this contrast to another blistering condition?
Bullous Pemphigoid
Pemphigus - affects the desmosomes - leading to intra epidermal skin splitting.
What the biggest cause of erythema multiforme?
HSV
What is the classification system used for cellulitis?
Enron system
What kind of rash does a Tick bite cause and what is the bacteria implicated in it?
Erythema Migrans
Borrelia Burgdorferi
Name a skin manifestation that comes about due to IBD and what are the symptoms:
Erythema Nodosum
Extremely painful across the shins.
Also associated Step infections
List several histological differences you would see in palmer skin vs skin from the arm:
Palmer skin:
- is thicker and contains Stratum lucidum
- there is lack of sebaceous glands
- Lack of hair follicles
Think skin:
- dermal papilla are much more pronounced
List some histological findings of Psoriasis:
Parakeratosis - retention of nuclei at top of the skin
Increased mitotic figures in the basal layer
Infiltration of lymphocytes and macrophages
Increased/ prominent capillaries
Describe the gross features of psoriasis:
Demarcated salmon pink coloured plaque with silver loose scale surrounding
- inflamed
- white scales
Define plaque:
Elevated superficial solid skin lesion that >1cm in diameter
What disease is associated with Telectangasia within the nails?
SLE
What is the pathophysiology underlying SJS?
Formation of a [Maculopapular rash] and Bullae
to the epidermis coming off the papillary junction due to apoptosis of the keratinocytes - induced by CD8 Cells
T cell mediated immune reaction.
- *this can only truly confirmed by biopsy of the skin where
- keratinocyte apoptosis will be seen
- peeling of the epidermis of the papillary junction
What are some common symptoms of SJS, some causes and how is it treated?
Prodrome - flu like symptoms
Peeling maculopapular rash with blistering across <10% of skin.
commonly affects oral/ gum area.
Treated with:
Admit to ICU
ABC approach
- removal of drugs or causes - and restrict any sulphur containing drugs
- Fluids IV - loss of fluid through burns
- Dressings
- Pain management
- Infection control - possible use of IV IgGs
- Special mattress protection
What are some characteristic findings of Erythema Multiform
Target lesion - which has a centre of blistering - which allows it to be differentiated from other target lesions.
Due to HSR most commonly associated with HSV
What tests would you carry out for Urticaria:
FBC
ESR
- checking for vasculitis
Eosinophil count
ANAs
Thyroid tests
- associated with underactive thyroid
