Dermatology Flashcards
What is the purpose of vernix caseosa?
Protects in utero skin from amniotic fluid
What are the skin defects in preterm infants?
Thin Poorly keratinized Lacks subcutaneous fat High water loss Cant sweat from birth onwards (takes few weeks)
What are the common naevi and rashes of the newborn?
Neonatal urticaria (erythema toxicum) -Few days after birth -White pinpoint papule at centre of red base -Mostly on trunk -contains eosinophils -resolves spontaneously Mongolian blue spots -Blue macules on buttocks and back -resolves spontaneously Milia -white pimples on face -from keratin and sebum retention in pilaceous follicles -resolves spontaneously Cavernous haemangioma (strawberry naevus) -common in preterm -resolve spontaneously -Rx excise if problematic -Complications - ulceration, bleeding Port wine stain (naevus flammeus) -dermal capillary AVM of face -can be from Sturge Weber syndrome Bullous impetigo -superficial Staph aureus infection -blistering -Rx with IV Abx Melanocytic nave (congenital moles) -6% risk of malignant melanoma -need to excise Albinism -melanin defect -ocular or oculocutaneous -no eye fixation in newborn -photophobia and nystagmus -Complications - blindness, skin cancer Epidermolysis bulls -blisters in skin and mucosa -AR types are more serious -Rx avoid trauma at all costs, Abx for infections -Complications - digit fusion, contractures, strictures Collodion baby -Dry scaly skin ichthyosis -parchment like skin -Rx Emollients to moisturise
What is SJ syndrome?
Severe bulls erythema multiforme
Skin, mucosa and eyes
Caused by drugs or infection
Complications - infection, AKI
What are the causes of erythema multiform?
Herpes simplex Mycoplasma Drugs Idiopathic (target lesions with central papule and red ring)
What are the causes of erythema nodosum?
Tender nodules over legs Strep infection Primary TB IBD Drugs Idiopathic Sarcoidosis
What are the rashes of infancy?
Napkin rash (irritant dermatitis from urine)
-clean, apply emollient, topical steroids
Infantile seborrheic dermatitis
Atopic dermatitis/eczema
What are the causes of napkin rash?
Urine
Infantile seborrheic dermatitis
Candida (involves skin flexures, with satellite lesions)
Atopic dermatitis
What is seborrheic dermatitis?
Erythematous scaly eruption on scalp
Within 2 months age
Lesions covered by yellow layer (cradle cap)
Spreads to the neck, axillae and groin
Not itchy, does not irritate child
Increases risk of later atopic eczema
Rx emollients, sulphur salicylate ointment, topical steroid
What is atopic eczema?
Affects 20% Genetic skin barrier defect Onset in infancy, after 2 months age Itch scratch itch cycle Dry skin with lichenification and skin markings FHx of atopy 1/3 develop asthma Breastfeeding can delay onset Resolves by age 12 High IgE, skin prick test Complications- severe staph infection, eczema herpeticum, LN Rx- avoid irritant, cows milk, cut nails, cotton clothes only, emollients, avoid soap, 1% HCT topical bd, occlusive bandages with zinc, Abx and acyclovir, antihistamines, dietary elimination, support
What are the common itchy rashes?
Atopic eczema Herpes zoster Urticaria Contact dermatitis Scabies Fungal infections Pityriasis rosea
How does atopic eczema change with age?
Infants - face, scalp, trunk
Older child - skin flexures, neck, wrists, ankles
What are the common skin infections and infestations?
Bullous impetigo
Viral warts (HPV, Rx - watch wait, cryo, salicylic acid)
Molluscum contagiosa (poxvirus, pearly papule with central umbilication, Rx - watch wait, cryo)
Ringworm (dermatophytes, anti fungal, treat pets)
Scabies (sarcoptes scabiei, stratum corneum, pruritus worse at night, burrows on skin, Rx to entire family permethrin cream)
Pediculosis (head lice, itchy scalp with LN, malathion)
What is pityriasis rosea?
Benign acute self limiting within 4 weeks
Single round scaly macule somewhere (herald patch)
Then smaller dull pink macules in fir tree pattern along ribs
