Acne and Rosacea Flashcards
what is acne vulgaris
chronic inflammatory disease of the pilosebaceous unit
define pilosebaceous unit
The structure consisting of hair, hair follicle, arrector pili muscles and sebaceous gland is an epidermal invagination known as a pilosebaceous unit.
acne pathophysiology
thickening of keratin lining and obstruction of sebaceous duct results in closed and open comedones (white and black heads)
what is the difference between white and black heads
none, black are open comedones
black colour due to melanin???
what happens to sebum secretion in acne
increased
what bacteria is increased in colonisation in acne
Propionibacterium acne (Corynebacterium)
where does inflammation occur during acne
around sebaceous gland
is acne more common in males or females
males
spots seen in acne
- Several types of acne spots occur, often at the same time e.g. inflamed papules, pustules and nodules, or non-inflamed comedones and pseudocysts
- Open and closed comedones are black and white heads
- Pustules are white or yellow ‘squeezable spots’
secondary lesions in acne
- Scars
- Excoriations (picked or scratched spots)
- Erythematous macules (red marks from recently healed spots, best seen in fair skin)
mild acne
scattered papules and pustules, comedones
moderate acne
numerous papules, pustules and mild atrophic scarring
severe acne
cysts, nodules, significant scarring
what beneficial effect do cleansers have on mild acne
dissolve the keratin plug of the comedones, mild acne may respond well to these
topical treatment ladder for acne
- Benzoylperoxide – bacteriostatic effects
- Keratolytic and anti-bacterial
- Topical vitamin A derivative (retinoid) – drying effect
- Anti-inflammatory and comedolytic
- Topical antibiotics (with one of the above)
- Antibacterial and anti-inflammatory
- Clindamycin and erythromycin
what is the effect of the topical vitamin A derivative
drying
systemic treatment ladder for acne
- ABx - tetracycline
- antibacterial and anti inflammatory
- isotretinoin (oral retinoid)
- anti inflammatory and sebum reducing properties
how long must oral tetracycline be taken for
6 months
where does isotretinoin act on
sebaceous glands
what is the effect of tetracycline
anti bacterial and also has an anti inflammatory effect after a few weeks
side effects of oral retinoid (isoretinoin)
- initally aggravates acne
- severe dry skin and lips, dryness of eyes - conjuncivitis
- dryness of mucous membanes
- teratogenic - women must be on contaception
what drugs can cause an exacerbation of acne
oral steroids
rosacea
- Chronic rash involving the central face that most often affects those aged 30 to 60. It may be transient, recurrent or persistent
what is rosacea characterised by
facial flushing, persistent erythema, pustules, oedema, inflammatory papules, telangiectasia
no comedomes
aetiology
- Genetic, environmental, vascular and inflammatory factors
- Skin damage due to chronic exposure to UV radiation is implicated
- Cathelicidins are observed in high concentrations in rosacea
what can happen in chronic rosacea
rhinophyma
what is rhinophyma
skin texture become coarse resulting in gross thickening and hypertrophy
commonly seen in men
what mites are inc in number in rosacea
demodex mites in sebaceous ducts
what are the pathological features of rosacea
vascular ectasia, patchy inflammation, pustules, perifollicular granulomas
name some other associated features of rosacea
conjunctivitis, blepharitis, eyelid oedema
what are some pre rosacea features
flushing may precede the other signs by some years – flushing is exacerbated by stress, alcohol and spices. As the disease progresses the flushing may be replaced by permanent redness.
what are some topical therapies for rosacea
metronidazole, ivermectin (dermodex mite)
what is the purpose of ivermectin
to reduce dermodex mite
oral therapy for rosacea
tetracycline long term, isotretinoin low dose if severe
what is the first line treatment for rosacea
topical metronidazole gel
