dermatology p124 Flashcards
functions of skin
Provides an anatomical barrier
Main method of Heat Regulation
Sensory input from the body
Storage for lipids and water
Drug absorbtion and waste excretion
flora on skin
Normal skin has commensal flora inhabiting healthy
skin
oilier the skin = approx 10x as many organims
➡ Staphylococci (S. Epidermis)
➡ Candida Albicans - commensal in some -
pathological in others
Oily skin has greater sebum secretion, bacterial
colonisation and keratinsation
comedones
aka blackheads
feature of Acne Vulgaris
build up of keratin and sebum
Black pores oxidise giving them their appearance
furuncles and carbuncles
Pockets filled with pus
When grouped together - carbuncle
S. Aureus is the causative organism
Folliculitis is a furuncle with a hair follicle
Red painful and swollen
Drain pus
Antibiotics not always necessary
acne vulgaris
is a long-term skin disease that occurs when hair follicles
are clogged with dead skin cells and oil from the skin.
It is characterized by blackheads or whiteheads, pimples, oily skin, and possible scarring.
It primarily affects areas of the skin with a relatively high number of oil glands, including the face, upper part of the chest, and back.
The resulting appearance can lead to anxiety, reduced self-esteem and, in extreme cases, depression or thoughts of suicide.
Mainly teenagers - 80% affected
Late onset possible but is rare in both genders and particularly rare in men
Aetiology
- Follicular sensitivity to Testosterone ➡ Increase around puberty
impact of acne
Build up of comedones
➡ Propionibacterium Acnes overgrows and leads to infections and cysts
➡ Scars can form if cysts rupture
self esteem, confidence
factors contribute to acne
puberty - inc testosterone
some contracetpive pills
greasy skin cleansers
systemic steroid tx
some anticonvulsant drugs
squeezing spots
local managment of acne
reduce excess skil oil - cleansers - gentle soap
antibacterials - benzoyl peroxide, retinoids (vit A), antibiotic lotions
systemic managament of acne
antibiotics (tetracyline based e.g. Minocyclin)
retinoids - isoteretinoin
hormone manipulation - anti-androgens (cytoterone)
eysipelas
Streptococcus Pyogenes
Defined by sharp raised border
- May blister and peel
Usually systemic symptoms
- Fever
- Rigor
Managed with systemic antibiotics
Can progress to Necrotising Fasciitis
Septic Shock
doesn’t have pus but instead goes very red
impetigo
Highly infections skin disease
- often seen in children, very common
- Staphylococcal or Streptococca*
Crusty red blister appearance
- Often associated with Eczema
Treated with topical antibiotics, Sometimes systemic antibiotics
Antibiotic choice found from culture
herpes simplex
viral
Usually affects a single dermatome or adjacent ones,
Activated by trauma
- Physical
- Chemical
- UV light
Run down feeling
Treat w/ Aciclovir
shingles
a.k. Herpes Zoster/Varicella Zoster
‘Recurrent’ HZV
Affects SINGLE DERMATOME
Causes SIGNIFICANT pain
- Neural inflammation from virus in the nerve
Pain may persist after rash has gone
- Post herpetic neuralgia
Treat with HIGH DOSE Aciclovir
molluscom contagiosum
Poxvirus, responsible for MC
DNA virus that replicates in the cytoplasm of infected cells
Benign and affects males more than females and immunocompromised patients
It is possible for it affect the oral cavity (buccal mucosa, lips and palate)
can be extensive if concurrent HIV
warts/verrucas
Associated with HPV (Human Papilloma Virus)
- Types 1-3 cause most warts
- Types 16 & 18 cause cervical cancer
Contact spread!
Treat w/ - Keratolysis, cryosurgery, excision
Most immune competentn people respond spontaneously
measles
Measles is a highly contagious infectious disease caused by the measles virus
Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days
Initial symptoms typically include fever, often greater than 40°C cough, runny nose, and inflamed eyes.
rubella
Caused by the Rubella virus
slightly duller rash than that of measles
can have associated lymphadenopathy and in adults joint pain
clasically only lasts 3 days
fifth disease
Caused by Parvovirus B19
So called because its the 5th most common child rash causing illness
roseola
Caused by either Human Herpes Virus 6 (HHV-6) or HHV-7
Usually associated with Leukopenia
Transmitted via saliva
hand foot and mouth
Associated with Cocksackievirus A16
Enterovirus 71 is the second most common
Commonly seeen around aged 10
Athlete’s foot
Typically affect feet between toes
groin involvement also common
Usually mixed fungal and bacterial infection
Scaling & sogginess of the skin
Prevent by keeping skin clean dry and damage free
Treat with antifungal/antibacterial cream (miconazole)
onchoylsis
Nail bed fungal infection
Usually Tinea unguium infection
Nail becomes malformed, thick and crumbly
May be seen with athlete’s foot
ringworm
Can affect different parts of the body
Groin - tinea curis > often spread from feet
Body - tinea corporis
Scalp - tinea capitis
- Inflammation of scalp leading to hair loss, Mainly in young children
Can be caught from infected animals
intertigo
Fungal infection due to chafing in moist
body folds:
- Under breasts
- Armpits
- Inner thighs
Treat with topical antifungal cream:
- Clotrimazole
- Miconazole
pityriasis versicolor
Caused by Pityrosporum orbiculare
- Usually a harmless commensal/ Also involved in ‘cradle cap’
Excessive growth causes the condition
- Results in patchy skin pigmentation - Pale red or brownish
Treat with topical or systemic antifungal
- Topical ketoconazole (in wash or shampoo)
- Systemic Itraconazole
apply to the WHOLE body from the chin down including under the nails
Treat ALL close contacts whether obviously infected or not
scabies
Infection with the ‘Scabies Mite’ > Sarcoptes scabiei
- From contact with an infected individual
- (skin-to-skin) ➡ Occasionally from bedding
- Usually 10-12 mites infect the host
- 3 eggs a day for life of mite – up to 2 months
Burrows appear on the skin
- Folds between fingers & on wrists
ITCH is often most troublesome feature
- More severe at night
- On trunk and limbs
RASH appears on trunk and limbs
- Tiny red intensely itchy bumps
- May get secondary impetigo
Rash and Itch are ALLERGY - can persist long after infestation gone
Treatment
- Chemical Insectisides (Scabicides)
- Benzyl Benzoate
- Permethrin
- Malathion
psoraisis
Papulosquamous skin disorder - immune mediated
- Often associated with Reiter’s, IBD, Pemphigus and Pemphigoid
- May develop psoriatric arthritis
Lithium Antimalarials, Beta-Blockers and Streptococcal
infection can cause it
Thick silvery scales covering an erythematous plaque and
typically involving multiple body sites
local tx of psoraisis
- Hydrocortisone
- Vitamin D3 analogue
- Retinoids
- Salicylic acid
- Calcineurin inhibitors (Ciclosporin and Tacrolimus)
> PUVA (psoralen and ultraviolet A)
systemic tx of psoraisis
drugs to reduce cell turnover
- methotrexate
- ciclosporin
- aitrein
- infliximab
- etanercept
pemphigoid
Subepithelial immunologically mediated bullous disease
1) Bullous Pemphigoid
- Tense blisters on normal skin or an erythematous base
- Usually on flexor surfaces
- Oral Lesions uncommon but can happen
- Attacks Hemidesmosomal Major and Minor BMZ antigens
- High levels of IgG and Eosinophils in the subepithelial
- layer
- Topical Corticosteroids best
- Failing that
➡ Dapsone (If neutrophil predominant infiltrate)
(Combo of Tetracycline and Nicotinamide)
➡ or immunesuppressants like Azathioprine
2) Mucous Membrane Pemphigoid
- MMP is a subepithelial bullous disorder mainly of late middle age
- Oral Lesions
- Desquamative gingivitis
- Erythematous/Erosive Lesions
- Sometimes blood filled blisters
- Chronic conjunctivitis
- Systemic Prednisalone and Topical Hydrocortisone in a vacuum custom tray for the gingival lesions work well
pemphugus
Autoantibodies attack surface antigens on keratinocytes
Acantholysis occurs (loss of intercellular connections) > Absent in Pemphigoid so is a useful diagnostic tool
Forms subepithelial blisters like in Pemphigoid
1) Pemphigus Vulgaris
- Most frequent form of pemphigus
- Usually in 40’s-60’s
- Correlation with Mediterranenan and Jewish ancestry
- Association with HLA (Human Leukocyte Antigen) Allotypes
- Begins with painful non healing ulcers in the mouth
- Lesions progress to face scalp and upper torso
- If left untreated will lead to death from metabolic consequences
- Treated with Systemic Corticosteroids
- ➡ Immunosuppresants like Methotrexate, Cylcophosphomide and Azathiorprine also used
2) Pemphigus Foliaceus
- Superficial form of pemphigus afffecting skin and lacking mucosal involvement
- blisters below the stratum corneum
- only ab to Desmoglein 1 found in Pemphigus Foliaceus
3) Paraneoplastic Pemphigus
- Severe mucosal involvement and various cutaneous lesions associated with mainly malignant neoplasms
- Associated with CLL, Hodgkins and Non-Hodgkin’s Lymphoma, Waldenström’s Macroglobulinaemia
- Characterised by its severe erosive lesions and ulcerations for the entirety of the oral cavity, tongue and lips, they are often very crusty too
- Polymorphic cutaneous lesions usually affecting upper half of the body including arms
- Lichenoid and Erythema Multiforme like lesions with transformations very common
epidermolysis bullosa
*genetic disorder* where randomisation occurs in the coding for the skin
- faults in the genes mean the basement membrane mean the epidermis and dermis seperate
Very challenging disease for young families to deal with and extremely distressing
Types
- EB Simplex - usually confined to palms and soles
- Junctional EB - very severe form in infants usually, can have severe oral implications
- Dystrophic EB - Also known as butterfly child, due to the fragility of the skin in these patients
- EB Acquisita * - Is the autoimmune form of the disease that occurs in response to minor injury
oral lichen planus
types
usually occurs with genitals haivng concurrent lesions
4 main kinds
- Reticular - White reticulated scale known as Wickham’s Striae
- Papular - looks like white taste buds on oral mucosa
- Erosive - Sore red pitted lesions with white reticular border
- Erythematous - Ditto above but with less reticulation and shallower
oral lichen planus
aetiology
- Amalgam restorations
- Anti-diabetics, Antimalarials, Beta Blockers, NSAIDs
- Hepatitis C virus infection
oral lichen planus
tx
- Topical Corticosteroids for early oral lesions
- Oral Corticosteroids for systemic presentation
erythema multiforme
Acute inflammatory disorder, usually self limiting and recurrent
- EM Major, EM minor and Stevens-Johnson Syndrome all sub manifestations of it
Young adults 20-40 are the most commonly affected
“Target Lesion” - i.e like a bullseye on a dart board is the classic cutaneous presentation
Orally can vary from small ulcers to huge widespread erosive lesions
Can lead to patients not being able to eat speak or even open their mouths
