Dermatology Flashcards
How long does it take for a new fingernail and toenail to grow?
Fingernail = 3 months
Toenail = 6 months
What is a comedone and what are the types?
Open = black heads
Closed = White heads
What is excoriation?
Loss of epidermis following trauma
What is lichenification?
Well defined thickening of skin with accentuation of skin markings due to repeated rubbing and scratching
What is Auspitz sign and in what condition do you see it?
Peeling off of surface scale reveals regular areas of pinpoint bleeding
Psoriasis
What is koebner phenomenon and what conditions can you see it in?
Formation of lesions from pre-existing skin condition at site of trauma / irritation. E.g. Psoriasis, vitiligo
What is impetigo and what causes it?
common superficial bacterial infection - usually staphylococcus aureus and streptococcus pyogenes
What are the three types of impetigo and their causes?
Bullous - staph
Crusted / Non-bullous either staph or strep
Ulcerated - strep
What are some complications of impetigo?
Acute glomerulonephritis
RHD
SSS
Cellulitis
Toxic shock syndrome
What is the management of impetigo?
- Use wet compressions to remove crust
- Good hygiene
- Cover affected areas
- Keep home from school (until lesions crusted over or had 24hrs of treatment)
- Separate towels and launder in hot water
- Muciprocin 2% ointment
- Abx for serious infections e.g. flucloxacillin
What is ecthyma and how is it treated?
Deep form of impetigo with ulcers forming beneath crusted sores. Scars and treated with oral Abx
What are some signs of folliculitis?
Tender red papule, with surface pustule centered on a hair follicle
What is furunculosis?
Deep form of folliculitis (usually staph)
What is the difference between steven johnson syndrome and toxic epidermal necrolysis?
SJS = <10% body surface area
10 - 30% = overla
TEN = >30% body surface area
Erysipelas vs Cellulitis. What is the difference?
- Erysipelas is upper dermis and superficial lymphatics
- Cellulitis is lower dermis and subcut tissue
- Cellulitis is less marginated
What is the Mx of cellulitis?
Rest and elevation of area
Mark outline
Analgesia
IV Abx - flucloxacilin
Compression bandage
What is the cause of molluscum contagiosum who gets it?
Poxvirus
Two peaks: Children 3-9 years and young adults
How is molluscum spread?
- skin to skin
- Indirect contact e.g. shared towels
- Auto-inoculation by scratching
- Sexual transmission
How do you describe molluscum?
Waxy pinkish look with small central pit
What are some DDX for viral exanthem?
Measles
Rubella
Varicella
Fifth disease
Roseola
Infectious Mononucleosis
Enterovirus infections such as hand foot and mouth
Pityriasis Rosea
Herpes zoster and simplex
Molluscum contagiosum
HIV
What is the clinical presentation of measles?
- incubates 7-14 days
- Infective 2 days prior to sx till 5 days
- URTI symptoms with fever and conjunctivitis
- Kopplik spots (white spots on mucosa)
- erythematous macular rash
What are some complications of measles?
Dehydration leading to death
Otitis media
Pneumonia
Encephalitis
What is congenital rubella syndrome?
Sensorineural deafness
CNS dysfunction
Cataracts
Cardiac defects
Where does the varicella virus remain dormant before reappearing as shingles / herpes zoster infection?
Anterior Horn cells of spinal cord
What type of lesions does varicella typically present as?
Vesicles - itchy
What is the distinguishing feature of fifth disease (parvovirus infection)?
“slapped cheek appearance” - firm red cheeks which feel burning hot
What pathogen causes hand, foot and mouth disease?
Coxsackie virus
What are some symptoms of roseola?
High Fever, URTI and red maculo-papular rash appearing as fever subsides
What are some complications of herpes zoster and management?
Post-herpetic Neuralgia
Corneal damage
Encephalitis
Anti-viral medication within 72hrs
How do you describe meningococcal infection in terms of skin symptoms and describe the bacteria?
Haemorrhagic rash with petechiae and then purpura on trunk and limbs
Gram negative coccus
HSV 1 is associated with ______?
HSV 2 is associated with ______?
HSV 1 = facial infections (cold sore)
HSV 2 = genital
How can you treat oral HSV (cold sores)?
Topical antiviral (acyclovir)
What is tinea called in the following locations?
1 - head
2 - body
3 - groin
4 - foot
1 - Tinea Capitis
2 - Tinea Corporis (ring Worm)
3 - Tinea Cruris
4 - Tinea Pedis
What is the cause of tinea pedis?
Swimming pools, showers and occlusive foot wear
What does pyoderma mean?
Any skins disease that is pyogenic
What does pityriasis versicolor look like and who does it commonly affect, and how can it be treated?
Hypopigmented scaly patches
Affects Indigenous people and treated with ketoconazole shampoo
What is SLE?
Autoimmune disease leading to inflammation of connective tissue
Burkholderia pseudomallei is what type of bacteria?
Gram negative
How do you treat head lice?
Wet combing (conditioner) with fine tooth comb
How does scabies present and what is the treatment?
Itch worse as night
Pruritic excoriated nonspecific rash on trunk
Treat with permethrin cream
What is the management of atopic dermatitis?
Life style - avoid hot baths, cold weather exacerbates
Use moisturizers (greasier is better)
Avoid perfume emollients
Topical corticosteroids
What is the management of nappy rash?
Use disposable nappies
Increase frequency of changing nappy
Apply barrier cream at every change
Treat any candida infection
Let child spend as long as possible without nappy on
Creams are ____ based: non greasy
Ointments are _____ based: greasy
Gels and lotions are _____ based
Water based
Oil Based
Alcohol Based
What are the causes of koilonychia?
Iron deficiency Anemia
Haemachromatosis
What are the causes of splinter haemorrhages?
Trauma
Infective endocarditis
Psoriasis
What are some causes of terry nails?
Cirrhosis
CHF
Diabetes
Who gets necrobiosis lipodica?
Diabetic patients
How do you describe psoriasis lesions?
Well defined salmon-pink plaques with large adherent centrally located silver scale
Affect body symmetrically
What are the causes of psoriasis?
Family Hx
Strep infections
Trauma (koebner phenomenon)
Medications such as BB, Lithium, prednisolone withdrawal
Excess alcohol consumption
Metabolic Syndrome
Stress
What are some DDX of psoriasis?
Tinea
Folliculitis
Dermatitis
Skin Cancers
Pityriasis Rosea
What is the management of psoriasis?
Education of chronicity
Modify lifestyle / exacerbating factors (stress, smoking, alcohol, weight loss)
Topical anti-inflammatories - Dithranol, tar, steroids, vit D
Specialist referral
Phototherapy (PUVA)
Can use systemic treatments (Methotrexate, cyclosporins, retinoids, biologic agents)
Far sightedness is called _____ and corrected by _____ lens
Hyperopia
Convex
Short sightedness is called ______ and corrected by ____ lens
Myopia
Concave
What is erythroderma and why is it a skin emergency?
Erythema and scaling involving >90% of skin surface
Causes high-output cardiac failure, hypothermia and dehydration
What is the DRESS clinical triad?
High fever
Organ involvement
Extensive skin rash
What is the characteristic feature of erythema multiforme and what is the most common causes?
Target lesions
HSV2, CMV, EBV
What is the main management of erythema multiforme?
antivirals
What are the treatment options of acne?
Education - avoid squeezing, hot or humid environments
Retinoids
Topical antiseptic
Topical / oral Abx
Refer to specialist after 3-6 months of oral Abx not working
What is rosacea?
Chronic rash predominantly affecting central face of adults
What are some features of rosacea?
Pustules, papules, central facial erythema, telangiectasia
What aggravates rosacea?
Alcohol
Hot showers
Topical steroids
Sun exposure
Stress
What is the most common skin cancer?
BCC
Describe BCC look and features of it?
Red / translucent nodule with shiny or pearly rolled edge with central depression. Blood vessels across surface
Locally invasive, low potential to metastasize
What treatment options are available for BCC?
Excision
Liquid nitrogen cryotherapy
Topical Imiquimod cream
Curettage and cautery
Photodynamic therapy
Describe the clinical features of SCC?
Firm papule / nodule
Sometime tender
No pearly edge/ telangiectasia
Adherent crust
Advanced lesions - rolled edge with ulceration / bleeding
What are common sites for SCC?
H&N - lip, ear, scalp
What margins do you use for wide excision of SCC?
Low risk = 4mm
High risk = 6-10mm
How do you describe keratoacanthoma?
Well differentiated SCC - volcano shape with central keratotic plug
How do you describe melanoma?
Flat, usually pigmented, asymmetric macule changing in size, shape or colour
Often on trunk / limbs
What is hidradenitis suppurativa?
Chronic inflammatory skin condition affecting apocrine glands, particularly in the axillae
What are some risk factors for hidradenitis suppurativa?
Family Hx
Obesity and insulin resistance
Smoking
IBD
What is the cause of scarlet fever and what does the rash look like?
Strep throat / impetigo (GAS)
Appears 12-48 hours after fever
Starts below ears, neck, chest, armpits and groin
Rough sandpaper skin
By day 6 skin peels off and rash fades
