Dermatology Flashcards
What is eczema typically presented with?
erythema
pruritus (itchiness)
Xerosis (dry skin)
site of skin involvement
what are the risk factors that can cause eczema?
flagging gene mutation
age <5yrs
family history of eczema
allergic rhinitis
asthma
What investigation would you do for ppl with eczema?
*Clinical findings
Bloods - IgE levels
skin-prick testing
oral food challenge
trial elimination diet
patching testing
Skin biopsy
what sort of medication would you give for eczema patient?
emollients
topical steroids
topical antibiotics therapy
how would you know how severe is an eczema?
use a EASI score
-check the severity of Eczema
what’s the first line treatment for topical steroid uses?
Mild:
Hydrocortisone 1%
Moderate:
Betnovate RD
Eumovate
Potent:
Betnovate
Betacap
Very potent:
Dermovate
what is eczema herpeticum
viral skin infect cause by HSV / varicella zoster virus
presentation of eczema herpeticum
widespread, painful, vesicular rash
fever
lethargy
irritability
reduce oral intake
lymphadenopathy (swollen lymph nodes)
treatment for eczema herpeticum
immediate hospitalisation
aciclovir
What is psoriasis?
Chronic autoimmune condition that causes recurrent symptoms of psoriatic skins lesions
what would a psoriasis patient presented with?
Symmetrically distributed of dry, flaky, scaly, faintly erythematou skin lesion that appear in raised and rough plaques, scale is typically silvery white, except in skin folds where the plaques often appear shiny with a moist peeling surface.
* commonly over the extensor surfaces of the elbows and knees and on the scalp
–> Auspitz sign - small points of bleeding when plaques are scraped off
–> Koebner phenomenon - development of psoriatic lesions to areas of skin affected by trauma
–> Residual pigmentation of the skin after the lesions resolve
what is Guttate psoriasis
small raised papules across the trunk and limbs.
They’re mildly erythematous
triggered by a streptococcal throat infection
what would a plaque psoriasis presented with?
thickened erythematous plaques with silver scales
seen on the extensor surfaces and scalp
which types of the psoriasis that are rare and requires admission to hospital?
Pustular psoriasis
Erythrodermic psoriasis
What tool can be used to assess psoriasis?
PASI score
what are the management for psoriasis?
- Topical steroids
- Topical vitamin D analogues (calcipotriol)
- Topical dithranol
- Topical calcineurin inhibitors (tacrolimus) are usually only used in adults
- Phototherapy with narrow band ultraviolet B light is particularly useful in extensive guttate psoriasis
List 2 product that are commonly prescribe by specialist for psoriasis
Dovobet
Enstilar
what is the pathophysiology of acne?
the sebaceous glands increase production of sebum(natural skin oils and waxy substance) which traps the keratin (dead skin cells) and block the pilosebaceous unit (pockets within the skin)
this causes swelling and inflammation
which hormones is responsible for the production for sebum?
Androgenic hormones
define the following terminology:
- Macules
- Papules
- Comedomes
- Ice pick scars
- hypertrophic scars
- Rolling scars
- Macules are flat marks on the skin
- Papules are small lumps on the skin
- Pustules are small lumps containing yellow pus
- Comedomes are skin coloured papules representing blocked pilosebaceous units
- Ice pick scars are small indentations in the skin that remain after acne lesions heal
- Hypertrophic scars are small lumps in the skin that remain after acne lesions heal
- Rolling scars are irregular wave-like irregularities of the skin that remain after acne lesions heal
What are the treatments for acne
- Topical benzoyl peroxide reduces inflammation, helps unblock the skin and is toxic to the P. acnes bacteria
- Topical retinoids (chemicals related to vitamin A) slow the production of sebum
- Topical antibiotics such as clindamycin (prescribed with benzoyl peroxide to reduce bacterial resistance)
- Oral antibiotics such as lymecycline
- Oral contraceptive pill can help female patients stabilise their hormones and slow the production of sebum
What medication would be best for severe acne?
Oral retinoids
–> Isotretinoin
what are the side effect of using isotretinoin?
- Dry skin and lips
- Photosensitivity of the skin to sunlight
- Depression, anxiety, aggression and suicidal ideation
- (Rarely) Stevens-Johnson syndrome and toxic epidermal necrolysis)
what is exanthem?
widespread rash that is usually accompanied by systemic symptoms such as fever, malaise and headache.
usually caused by an infectious condition such as a virus
What causes exanthems
- Measles (measles virus)
- Scarlet Fever (group A streptococcus infection)
- Rubella (rubella virus)
- Dukes’ Disease
- Parvovirus B19
- Roseola Infantum (human herpesvirus 7 (HHV-7))
What is Erythema Multiforme
Erythematous rash caused by a hypersensitivity reaction.
common cause from viral infection and medications.
associated with Herpes Simplex Virus (HSV) and mycoplasma pneumonia
What is the presentation of Erythema multiforme?
widespread, itchy, erythematous rash.
- Target lesion (red rings within larger red rings, with the darkest red at the centre
- sore mouth (stomatitis)
- mild fever
- muscle and joint aches
- headaches
- general flu-like symptoms
What is the management for erythema multiforme?
usually resolves within one to four weeks without any treatment or lasting effects.
Severe cases
- may need to admission to hospital
- prednisone
Recurrent disease
acyclovir/aciclovir(antiviral therapy)
Complication of erythema multiforme
hyperpigmentation
Keratitis
Conjunctival scarring
Uveitis
Permanent visual impairment.
how to diagnosed erythema multiforme?
***based on history and clinical examination
- Complete blood
LFT
ESR
serological testing
Chest X-ray
Skin biopsy
recurrent EM –> HSV
What is shingles / herpes zoster
localised, blistering and painful rash caused by reactivation of varicella-zoster virus (VZV)
What is the pathophysiology of herpes zoster?
shingles…
VZV lies dormant with the dorsal root ganglia. When the immune system is weakened, it may extend out in a dermatomal distribution leading to the characteristic vesicular rash.
what are the Clinical features of shingles?
unilateral
erythematous
vesicular rash in a dermatomal distribution
Paraesthesia
pain
scarring
Hutchinson’s signs
what investigation can be made with patient that have shingles
- clinical diagnosis and appearance of the classical rash
- PCR testing –> VZV
- test for immunosuppression
what is the management for shingles?
- Anti-viral therapy (aciclovir, valaciclovir, famciclovir), within 72 hours of rash onset
- analgesia
paracetamol / NSAIDs
amitriptyline, gabapentin - hospital admission
- good hygiene
- vaccination
complication of shingles
- Post-herpetic neuralgia
scarring
secondary bacterial infection
ramsay hunt syndrome
herpes zoster ophthalmicus
motor neuropathy
CNS: encephalitis, meningitis
folliculitis
> cause by
> symptoms
> risk factor
> treatment
> staphylococcus aureus
papules, pustules, or cysts around the hair follicles
warm moist skin, irritation of the skin (shaving/drying)
anti-septic treatment (dermol)
deep / persistent lesion - systemic antibiotics (tetracyclines)
recurrent infection - mupirocin (bactroban)
Cellulitis
> cause by
> symptoms
> treatment
> Strep. pyogenes & strep. aureus
Spreads rapidly, common on the leg; red, painful, hot, swollen skin
first line - flucloxacillin 500mg QDS; clarithromycin 500mg BD if penicillin allergy
facial cellulitis - co-amoxiclav
Impetigo
> common in what population?
> cause by
> how long it should resolve?
> symptoms
> what complication will this can lead to ?
> treatment
> children
strep. aureus / group a strep
within 2-3 weeks
various forms: bullous, vesicular / pustular
bullous - large, flaccid bullae erythematous
non- bullous - vesicular lesion and pustules with ‘honey colour crust’
Ecthyma; acute post streptococcal glomerulonephritis; staphylococcal scalded skin syndrome
cover affected area
- wash hands regularly
- separate towels
- First-line –> fusidic acid 7-10days
if resistance –>mupirocin
Hidradenitis suppurativa
> what is it?
> where it affects
> appearance
> investigation
> treatment
> chronic follicular occlusive disorder that affects the apocrine glands
axillary, groin, perianal, perineal, inframammary skin
papules, pustules, inflammatory nodules, deep fluctuant abscesses, draining sinuses, severe band-like scars
bacterial culture, skin biopsy
antibiotic therapy, corticosteroid, incision and drainage
Herpes simplex (HSV)
> difference of HSV 1, HSV 2 and cutaneous herpes
> acquired from ?
> symptoms
> investigations
> treatment
> HSV 1 - oral herpes, fever, blister
HSV 2 - genital herpes
cutaneous herpes - herpes gladiatorum
direct contact, droplets, infected secretion entering the skin / mucous membranes
lymphadenopathy, dysuria(in women), genital ulcer, oral ulcer, tingling sensation
HSV polymerase chain reaction (PCR), viral culture, Glycoprotein G-based type-specific serology (gG1 and gG2)
aciclovir, valaciclovir / famciclovir
Warts
> cause by?
> types of warts
> what factor increases the risk of inoculation
> symptoms
> investigations
> treatment
> Human papilloma virus (HPV)
common, plantar, plane, genital
damaged epithelium
lesion growth over weeks to months; round raised papule; tiny black dots on surface of lesion; hyperkeratosis; greyish-white / light brown colour
skin biopsy, immunoperoxidase stain, skin culture
no treatment, supportive management
- salicylic acid; cryotherapy; curettage and cautery
Fungal infection - Tinea / (dermatophyte infections)
> most ideal condition for fungal infections?
> cause by
> presentation
> types of Tinea
> investigation
> treatment
> warm, moist / thickly keratinised skin
Trichophyton & Microsporum species; yeast / candida
generic lesion are inflammatory and appear eczematous, flaky, red and itchy
corporis (body), pedis (foot), cruris (groin area), capitis (head)
potassium hydroxide microscopy; dermoscopy; fungal culture; PCR; wood lamp examination
milder cases of tinea - terbinafine / imidazole creams (miconazole)
- oral antifungals - allylamines, triazoles, imidazoles
Parasites - scabies
> cause by
> transmission pathway
> most common in?
> symptoms
> investigation
> treatment
> mite called sarcoptes scabiei var. hominis
skin to skin contact / sexually transmitted / clothing and beddings
children
generalised and intense pruritus, worse at night; burrows; papules, vesicles, excoriations; positive ink burrow test
ectoparasite preparation, skin biopsy, epiluminescence light microscopy
5% permethrin cream; antibiotics (flucloxacillin/ erythromycin if penicillin allergy)
Eczema
> Clinical features
> investigation
> treatment
Psoriasis
> characteristic
> pathophysiology
> factors that triggers it
> common area affected
> complication it can associate with
> treatment
> chronic, sharply demarcated, dull-red, scaly plaques, particularly on the extensor prominences and in the scalp. patches / flaky skin, itching
large T-cells triggers the release of cytokines –> inflammation
stress, alcohol, smoking, trauma, infection, drugs, pregnancy, sunlight
scalp
