Give two advantages of topical treatments?
- Direct application
2. Reduced systemic effects
Give three disadvantages of topical treatments
- Time consuming
- Correct dosage can be difficult
- Messy to use
What is a cream?
Semisolid emulsion of oil in water containing emulsifier and preservative
What is the term for a semisolid grease/oil (soft paraffin) containing no preservative?
Ointments
What do ointments restrict?
Transepidermal water loss
What is the term for a suspension or solution of medication in water, alcohol or other liquids - used to treat scalp and hair-bearing areas?
Lotions
What is another term for “thickened aqueous lotion”?
Gels
What is in a gel?
Semi-solids, containing high molecular weight polymers e.g. methylcellulose
What do emollients enhance and name a condition they are used for?
Rehydration of epidermis and used for all dry/scaly conditions such as eczema
How much emollient is prescribed weekly for patients?
300 - 500G
What is wet wrap therapy used for?
Very dry (xerotic) skin
Give the three mode of action points for topical corticosteroids?
- Vasoconstrictive
- Anti-inflammatory
- Anti-proliferative
Name a mild topical steroid?
Hydrocortisone
Name a moderate topical steroid?
Modrasone
Clobetasone
Butyrate
Name a potent topical steroid?
Mometasone
Betamethasone
Valerate
Name a very potent topical steroid?
Clobetasol
Proprionate
What could be used to treat eczema, psoriasis, lichen planus and keloid scars?
Topical corticosteroids
Give three side effects of topical steroids?
Thinning of the skin, purpura and stretch marks
What are fixed telangectasia, steroid rosacea and perioral dermatitis all side effects of?
Topical steroids
What antiseptic is used in acute exudative eczema, pompholyx?
Potassium permanganate rinse/soak/bath
Name three topical antibiotics used for acne?
Clindamycin
Erythromycin
Tetracycline
Name a topical antibiotic used for rosacea?
Metronidazole
Name two topical antibiotics used for impetigo?
Mupirocin
fusidic acid
Name a disease where a topical antiviral would be used?
Herpes simplex
Name two conditions where oral antivirals would be used?
Eczema herpeticum
Herpes Zoster
Name two treatments for candida?
Nystatin
Clotrimazole
Name two treatments for dermatophytes (ringworm)
Clotrimazole
Terbinafine cream
Name a treatment for pityriasis versicolor?
Ketoconazole
What is menthol?
An antipruritic
What do keratolytics do?
Soften keratin
What drug type would be used for viral warts, hyperkeratotic eczema & psoriasis, corns and calluses and to remove keratin plaques in scalp?
Keratolytics
What is used to treat genital warts?
Podophyllin
What are formaldehyde, glutaraldehyde and silver nitrate all used for?
Treatment of warts
Give 5 options for topical psoriasis treatment?
Coal tar Vitamin D analogue Keratolytic Topical steroid Dithranol
What drug is an immune response modulator, ehances innate and cell-mediated immunity and has anti-viral/anti-tumour effects?
Imiquimod
What (trade name Aldara cream) is used for genital warts, superficial BCC and also solar keratoses, lentigo maligna, Bowen’s disease and verrucae?
Imiquimod
What do calicneurin inhibitors do?
Suppress lymphocyte activation
Give two examples of calicneurin inhibitors and a condition they are used for?
Tacrolimus
Pimecrolimus
Atopic eczema
What is increased thickness of keratin called?
Hyperkeratosis
What is parakeratosis?
Persistence of nuclei in the keratin layer
What is acanthosis?
Increased thickness of epidermis
What is papillomatosis?
Irregular epithelial thickening
What is spongiosis?
Oedema between keratinocytes
What cells are involved in inflammatory cell infiltrate?
Lymphocytes and/or neutrophils
Give four features in the acute phase of eczema?
- Papulovesicular
- Red erthematous lesions
- Oedema (spongiosis)
- Ooze or scaling and crusting
Give three features of the chronic phase of eczema?
- thickening (lichenification)
- Elevated plaques
- Increased scaling
What is itchy, ill-defined, erythematous and scaly?
Eczema
What is the pathogenesis and histology of contact allergic dermatitis?
Delayed type 4
Spongiotic dermatitis
What is the pathogenesis and histology of contact irritant dermatitis ?
Trauma e.g. soap
Spongiotic dermatitis
What is the pathogenesis and histology of atopic dermatitis?
Genetic and environmental factors resulting in inflammation
Spongiotic dermatitis
What is the pathogenesis and histology of drug-related dermatitis?
Type 1 or 4 hypersensitivity reaction
Spongiotic dermatitis and eosinophils
What is the pathogenesis and histology of photo-induced or photosensitive dermatitis?
Reaction to UV light
Spongiotic dermatitis
What is the pathogenesis and histology for lichen simplex dermatitis?
Physical trauma to skin - scratching
Spongiotic dermatitis and external trauma
What is the pathogenesis and histology of stasis dermatitis?
Physical trauma to skin - hydrostatic pressure
Spongiotic dermatitis and extravasation of RBCs
What type of dermatitis can a button on jeans cause?
Nickel contact allergic dermatitis
In the immunopathology of contact allergic dermatitis - what do Langerhans cells in the epidermis do?
Process antigen (increased immunogenicity)
In the immunopathology of contact allergic dermatitis - what happens after the Langerhan cell has processed the antigen?
It is presented to the Th cells in the dermis
In the immunopathology of contact allergic dermatitis - what happens after the processed antgen has been presented to the Th cells in the dermis?
Sensitised Th cells migrate into lymphatics and then to regional nodes where antigen presentation is amplified
In the immunopathology of contact dermatitis - what happens after subsequent antigen challenge?
Specifically sensitised T cells proliferate nad migrate to and infiltrate skin causing dermatitis
What can be used to test contact dermatitis?
Patch testing
What type of dermatitis is a non-specific physical irritation rather than a specific allergic reaction?
Irritant dermatitis
What is nappy rash?
Irritant contact dermatitis to urine - sparing of flexures
What type of eczema involves pruritis, ill-defined erythema and scaling, generalised dry skin, flexural distribution and is associated with asthma?
Atopic eczema
Give three chronic changes with atopic eczema?
Lichenification
Excoriation
Secondary infection
In eczema secondary infection - what does crusting indicate?
Staph aureus infection
What is eczema herpeticum an infection of and what should you look for?
Herpes simplex virus
monomorphic punched-out lesions
What are the five UK diagnostic criteria for atopic eczema?
Itching plus 3 or more:
visible flexural rash history of flexural rash personal history of atopy generally dry skin onset before age 2
The 7 treatments for eczema?
- PATTPSB
- Plenty of emolients
- Avoid irritants
- Topical steroids
- Treat infection
- Phototherapy - UVB
- Systemic immunosuppressants
- Biologic agents
What is the most important gene in atopic eczema?
Filaggrin
What is another term for photosensitive eczema?
Chronic actinic dermatitis
What three things is stasis eczema secondary to?
- Hydrostatic pressure
- Oedema
- Red cell extravastion
What type of eczema has spongiotic vesicles?
Pompholyx eczema
What type of eczema can be caused by repetetive scratching?
Lichen simplex
Describe staphylococcus?
Gram positive cocci in clusters
Give the two important types of Staphylococcus?
- Staph aureus (coagulase positive)
2. Coagulase negative Staph (epidermidis, saprophyticus)
What is an enzyme, produced by staphlycoccus aureus, that clots plasma?
Coagulase
What causes urinary tract infection in women of child-bearing age?
Staph. saprophyticus
How are streptococcus species classified?
By haemolysis on blood agar
What haemolysis is complete?
Beta
What toxin that damages tissues does beta-haemolytic streptococci release?
Haemolysin
What are the two important catagories of alpha-haemolytic streptococci?
Strep. pneumoniae
Strep. viridans
Give an example species of non-haemolytic streptococci?
Enterococcus species - commensals of bowel
Along with cellulitis, wound infection and other minor skin sepsis - what other bacterial skin infections are caused by Staph. aureus?
Infected eczema, impetigo and staphylococcal scalded skin syndrome
What bacterial skin infection does Strep pyogenes (Group A strep) cause?
Necrotising fascilitis
Erysipelas
What is a bacterial infection spreading along fascial planes below the skin surface leading to rapid tissue destruction?
Necrotising fascilitis
What is another term for tinea pedis?
Atheltes foot
In dermatophyte pathogenesis - what occurs after fungus has entered abraded or soggy skin?
Hyphae spread in stratum corneum
What does increased epidermal turnover cause?
Scaling
What dermatophtte causal organism comes from cats?
Microsporum canis
What are two treatments for scalp infections?
Terbinafine orally
Itraconazole orally
How do you diagnose candida skin infection?
Swab for culture
How do you treat candida skin infection?
Clotrimazole cream
Oral fluconazole
What is scabies caused by?
Sarcoptes scabiei
What is the incubation period of scabies?
Up to 6 weeks
In scabies - where does the itchy rash affect?
Genital areas, figner webs and wrists
What are the two treatments for scabies?
Malathion lotion
Benzyl benzoate
Where does pediculus capitis affect?
Head louse
What is the treatment for lice?
Malathion
What disease is dermatomal?
Shingles
What disease is macules to papules to vesicles to scabs to recovery?
Chickenpox
What disease has a high mortality and is secondary to chickenpox in mother in late pregnancy?
Neonatal VZV
What does the later stage of shingles show?
Rash and increasing pain
What nerve can be affected by shingles?
Trigeminal
Where can you get vesicles and pain with Ramsay-Hunt syndrome?
Vesicles and pain in auditory canal and throat
What nerve facial palsy can you get with Ramsay-Hunt syndrome?
7th nerve palsy
In Ramsay-Hunt syndrome - which cranial nerve is irritated?
8th - deafness, vertigo, tinnitus
What virus occurs commonly in pre-school children, lasts around a week and gives primary gingivostomatitis and extensive ulceration in and around mouth>
Herpes simplex
What is it called when herpes simplex virus spreads to eczema?
Eczema herpeticum
What condition gives a blistering rash at the vermillion border?
Herpes simplex virus recurrence
What type of herpes simplex virus is the main cause of oral lesions?
Type 1
What is aciclovir an analogue of?
Guanosine
How is lab confirmation of herpes simplex virus obtained?
Swab with viral transport medium
What condition can be described with target lesions with erythema?
Erythema multiforme
What condition can be triggered by herpes simplex virus and mycoplasma pneumoniae bacterium?
Erythema multiforme
What condition gives fleshy, firm, umbilicated, pearlescent nodules 1 to 2 mm diamater?
Molluscum contagiosum
How can molluscum contagiosum be treated?
With liquid nitrogen
What is the laymans term for human papilloma virus?
Warts
What disease gives a blistering rash of back of mouth and is caused by enterovirus (coxsackie and echovirus)?
Herpangina
What is caused by parvovirus B19?
Erythema infectiosum or slapped cheek disease
Give three complications of parvovirus B19?
- Spontaneous abortion
- Aplastic crises
- Chronic anaemia
How is parvovirus B19 lab confirmed?
By antibody testing - parvovirus B19 IgM test
What is the virus of sheep “scabby mouth” disease?
Orf
What can be seen on a patient with Orf?
Firm, fleshy nodule on hands of farmers
What can be seen on a patient with primary syphilis infection?
Painless ulcers at site of entry
What can be seen on a patient with secondary stage syphilis infection?
Red rash over body
Prominent on soles of feet and palms of hands
Mucous membrane “snail track” ulcers
What is syphilis due to?
Sexually transmitted infection with bacterium Treponema pallidum
How is syphilis diagnosed?
Blood test or swab of chancre for PCR
How is syphilis treated?
Injections of penicillin
What is the bacterial cause of Lyme disease?
Borrelia burgdorferi
What is the early presentation of Lyme disease?
Erythema migrans
What is the late presentation of Lyme disease?
Heart block, nerve palsies and arthritis
How is Lyme disease diagnosed?
Blood test for antibody to organism
What type of HPV is most common in warts/veruccas?
1 -4
What type of HPV is most common in genital warts?
Types 6 and 11
What type of HPV is most common in cervical cancer?
Types 16 and 18
What is one of the most common genodermatoses?
Tuberose sclerosis
Give two clinical features of Tuberose sclerosis?
- Periungual fibromata
2. Longitudinal ridging
What condition may present as infantile seizures?
Tuberose sclerosis
What is the earliest cutaneous sign of Tuberose sclerosis?
Ash-lead macule
What type of mutation is Tuberose Sclerosis?
Autosomal dominant
Other than periungual fibromas, what 3 other tumours can arise in Tuberose Sclerosis?
- Facial angiofibromas
- Hamartomas
- Bone cysts
What are shagreen patches and enamel pitting seen in?
Tuberose Sclerosis
What two chromosomes are affected in Tuberose Sclerosis?
Tuberin - chromosome 9
Hamartin - chromosome 16
What does Tuberose Sclerosis show?
Genetic heterogeneity - mutation in TSC1 or TSC2
What is the penetrance like in Tuberose Sclerosis?
Variable
Name a group of genetic skin fragility conditions?
Epidermolysis Bullosa
What are the three main types of epidermolysis bullosa?
Simplex
Junctional
Dystrophic
What is EB aquisita?
A rare autoimmune condition
Describe haploinsufficiency?
Only one copy of working - reduced protein production
What term describes - expression of abnormal protein interferes with normal protien
Dominant negative
What are two clinical signs for neurofibromatosis type 1?
Cafe-au lait macules
Neurofibromas
What are plexiform neuroma, axillary and inguinal freckling, optic glioma, Lisch nodules and a distinctive bony lesion all features of?
NF1
What can filaggrin mutations cause?
Ichthyosis vulgaris
What part of the skin is stratified keratinising squamous epithelium?
Epidermis
What cells are in the corneal layer?
Differentiated keratinised cells
Where are melanocytes found?
Basal layer
What is the dermis a matrix of?
Type 1 and type 111 collagen
Name two ground substances found in the dermis?
Hyaluronic acid
Chondroitin
Where does the papillary dermis lie?
Just beneath the epidermis
What does the reticular dermis contain?
Appendage structures
What is the epidermal basement membrane made of?
Laminin and collagen IV
What is the term describing increased thickness of keratin layer?
Hyperkeratosis
What is the term describing persistence of nuclei in the keratin layer?
Parakeratosis
What is the term describing increased thickness of epithelium?
Acanthosis
What is papillomatosis?
Irregular epithelial thickening
What is the term for oedema fluid between squames appearing to increase prominence of intercellular prickles?
Spongiosis
What is psoriasiform?
Elongation of the rete ridges e.g. psoriasis
Give three aetiology points about acne vulgaris?
- Increased androgens at puberty
- Keratin plugging of pilosebaceous glands
- Infection with anaerobic bacterium corynebacterium acnes
In acne - what do keratin and sebum build up to produce?
Comedones (blackheads/whiteheads)
Is rosacea commoner in females or males?>
Females
What condition involves recurrent facial flushing, visible blood vessels, pustules and thickening of the skin (rhinophyma)?
Rosacea
Name four factors that can aggravate rosacea?
- Sunlight
- Alcohol
- Spicy food
- Stress
What condition has vascular ectasia, patchy inflammation with plasma cells, pustules, perifollicular granulomas as its pathology?
Rosacea
Give three important examples of immunobullous diseases?
- Pemphigus
- Bullous pemphigoid
- Dermatitis herpetiformis
What disease is rare autoimmune bullous, has loss of integrity of epidermal cell adhesion and responds to steroids?
Pemphigus
In the autoimmune condition - pemphigus vulgaris - what are IgG auto-antibodies made against?
Desmoglein 3
What does pemphigus vulgaris produce?
Fluid filled blisters which rupture to form shallow erosions
What process is common to all variants of pemphigus?
Acantholysis - lysis of intercellular adhesion sites
What pemphigus disease has subepidermal tense blistering and has no evidence of acantholysis?
Bullous pemphigoid
Describe the pathology of bullous pemphigoid
Circulating antibodies (IgG) react with a major/minor antigen of the hemidesmosomes anchoring basal cells to basement membrane. The result is local complement activation and tissue damage.
What autoimmune bullous disease has strong association with coeliac disease?
Dermatitis herpetiformis
What haplotype is dermatitis herpetiformis associated with?
HLA-DQ2
What condition has intensely itchy lesions - symmetrical, involves the elbows, knees and buttocks and the hallmark is papillary dermal microabscesses?
Dermatitis herpetiformis
Describe what is seen in chronic plaque psoriasis?
Sharply demarcated, scaly, erythematous plaques
Give four clinical features of psoriatic nail disease?
- Onycholysis
- Nail pitting
- Dystrophy
- Subungal hyperkeratosis
Name two vitamin D analogues for treatment of psoriasis?
- Calcipotriol
2. Calcitriol
In the treatment of psoriasis sometimes fumaric acid ester can be used -what does it disrupt?
Lymphocytes
Give three topical treatments for acne?
- Benzoyl peroxide - keratolytic, antibacterial
- Vitamin A derivative (retinoid) - adapalene
- Antibiotics - antibacterial and anti-inflammatory
Name an oral retinoid used for systemic treatment of acne?
Isotretinoin
Name two antibiotics used to treat rosacea?
Topical metronidazole
Oral tetracycline
Differentiate between bullous pemphigoid and pemphigus?
Bullous pemphigoiD - split is Deeper, through DEJ
PemphiguS - split is more Superficial, intra-epidermal
What disease is common in elderly patients, localizesd to one area, has large tense bullae on normal skin or erythematous base, blisters burst to leave erosions, itchy erythematous plaques and papules may be the presenting feature and Nikolsky sign negative?
Bullous pemphigoid
What disease typically affects scalp, face, axillae and groins, has thin roofed flaccid vesicles, lesions rupture to leave raw areas and is Nikolsky sign positive?
Pemphigus vulgaris
Name three immunosuppressive agents used to treat both pemphigoid and pemphigus?
Azathioprine
Ciclosporin
Mycophenolate
Suggest four ways to investigate anaphylaxis?
- Specific IgE specificity
- Skin prick testing
- Challenge test
- Serum mast cell tryptase level during attack
What three things mediate itch?
- Chemical mediators in skin
- Nerve transmission
- Central nervous system
What are the four causes of itch?
- Pruritoceptive
- Neuropathic
- Neurogenic
- Psychogenic
What type of itch is something (usually associated with inflammation or dryness) in skin that triggers it?
Pruritoceptive
What type of itch is damage of any sort to central or peripheral nerves causing it?
Neuropathic
What type of itch is caused by e.g. opiate effects on CNS receptors
Neurogenic
What type of itch is psychological with no CNS damage?
Psychogenic
Give 6 systemic diseases associated with itch
- Haematological
- Paraneoplastic
- Liver and bile duct
- Psychogenic
- Kidney disease
6 Thyroid disease
What are 5 anti-itch treatments?
- Sedative anti-histamines
- Emollients
- Antidepressants - doxepin
- Phototherapy
- Opiate antagonists