Dermatology Flashcards
What are the five most common organisms of red rash in paediatric patients?
Really Red Munchkins Scare Parents
R: Rubella – fever + 3 day descending rash
R: Roseola – macular rash starting at high fever resolution; starts on trunk
M: Measles – 4Cs: cough, conjunctivitis, corzya and Koplik spots
S: Scarlet Fever – S. pyogenes sandpaper-like rash with strawberry tongue within first 2 days; desquamation on palms and soles afterwards
P: Parvovirus B19 – “slapped-cheek” lacy rash following fever
What are some common infections in paediatric patients associated with rashes?
Really Sick Children Must Take No Exercise
R: Rubella (D1)
S: Scarlet fever (D2)
C: Chickenpox (D3)
M: Measles (D4) + Koplik spots one day before rash
T: Typhus, Rickettsia (D5)
N: Nothing
E: Enteric fever/Salmonella/Typhoid (D7) >> Number of days after fever onset that a rash appears
What are 3 organisms that cause rash specific to palm and soles?
You drive CARS with your palms and soles.
CA: Coxsackie virus A
R: Rickettsia rickettsii
S: Syphilis (secondary)
What is this lesion? What disease is it related with?
Erythema marginatum
- Asosciated with rheumatic fever
What are the presenting features of measles?
Prodrome of the three Cs:
- Cough
- Coryza
- Conjunctivitis
Rash
- ~4 days after start of symptoms
- Erythematous maculopapular rash
- Starts at the hairline and spreads down
- Sparing palms and soles
- Koplik spots in the mucosa ~1 day before rash
What are the presenting features for roseola (6th disease) by HHV-6?
High-grade fever with irritabilty and lymphadenopathy
Rash once fever subsides
- Blanching, pink maculopapular
- Starts at the neck and the trunk
- Spreads to the face and extremities
What is this lesion? What is it associated with?
Erythema multiforme
>> Fixed lesions for at least 7 days
>> Target lesions with damaged skin in the central zone
>> All lesions appear within 72 hours
- Infections: HSV, Orf virus, hisioplasmosis
- Drug reactions
- Non-Hodgkin lymphoma
- Connective tissue disorders
- Vasculitides
>> Severe major erythema multiforme: think toxic epidermal necrolysis
What are the possible causes of generalized itching?
- Anemia
- Iron deficiency
- Polycythemia rubra vera
- Lymphoma
- Hepatic failure
- Thyroid disease
- Drugs
>> Unbearable generalized itching: think malignancy
What is a bulla?
Vesicle (papule that contains clear fluid) >0.5cm
What is a macule?
Flat circumscribed discolouration (think cafe-au-lait spots)
What is a papule?
Elevated solid lesion <0.5cm
What is excoriation?
Linear erosion induced by scratching
What are the differences between erosion and ulcer?
Erosion: partial local loss of epidermis; heals without scar
Ulcer
- FULL thickness focal loss of epidermis and dermis
- Heals with scar
What is the difference between erythema and purpura?
Erythema: blanchable
Purpura: nonblanchable
How does one differentiate between diaper rash and Candida napkin dermatitis?
Candida
- Sharp margin with scaling
- Satellite lesions
- Involvement of intertriginous areas
>> Check oral cavity for oral flush
>> Treat with topical anti-fungal
What is this lesion?
Infantile seborrhoeic dermatitis
- Mainly affects:
>> Scalp
>> Face
>> Flexural areas - Cradle cap: yellow or white greasy scales
- Starts from 2-3 weeks and clears in a few weeks
>> Can also occur in adults
What is this lesion? How would one describe it?
Eczema/Atopic dermatitis
Some characteristics of eczema
- Erythema
- Oozing
- Excoriations
- Crusting
- Papulations
- Hyperlinearity due to thickened skin
What is the management for atopic dermatitis/eczema?
- Emollients
- Topical steroids
- Immunomodulating agents: topical VS. systemic
- Food/allergen avoideance
>> 90% onset before 5 years
>> Remission by age 15 in 90%
What is this lesion?
Eczema Herpeticum
>> PAINFUL!!!!
Management
- Admit
- Consult ophthalmologist
What is this lesion? What are the possible treatments?
Molluscum contagiosum
Management
- Cryotherapy
- Laser ablation
- Topical antivirals
What is this lesion? What is the treatment?
Scabies: highly contagious and pruritic
- Topical application of insecticides: lindane, sulphur
- Apply below the neck for older children
- Apply the whole body for infants and toddlers
- Treat all household members
What is this condition? What are the possible causes?
Stevens-Johnson syndrome
- Variable skin rash plus at least 2 mucosal lesions
>> Purulent conjunctivitis
>> Lip lesions
>> Perianal/urethral lesions
>> Look for blood in urine and stool
- Look for erythema multiforme
- Erythematous macules rapidly evolve into bullae, skin necrosis and denundation
Causes
- Drugs: NSAIDs, sulfonamides, anti-convulsants, penicillins, tetracyclines etc.
- Infections: HSV, mycoplasma etc.
What is this lesion?
Toxic epidermal necrolysis
- Detachment of the epidermis from the dermis all over the body
- Usually related to drug reactions
- Life-threatening
- Associated with Stevens-Johnson Syndrome
What are fixed drug eruptions?
A type of drug reaction that recur at the same site with each exposure of one particular drug
Possible drugs include:
- Aspirin
- Antibiotics: penicillin, tetracyclines and sulfonamides
- Anti-convulsants
If a non-palpable rash erupts after varicella infection, what are the differential diagnoses?
- Immune thrombocytopenic purpura (ITP)
- Henoch-Schonlein purpura (HSP)
>> CBC to rule out ITP
What is this lesion? What is the management for this lesion?
Hemangioma
Natural history
- Onset at first week of life
- Growth fastest at 6 months of life
- Involution begins at 12 months of life
- Complete involution
>> 50% by age 5 years
>> 70% by age 7 years
>> 100% by age 12 years
- Conservative: usually fades in a few years
- Propranolol: if it causes functional disability
Note: Hemangiomas VS. tufted angiomas
>> Tufted angiomas rarely self-involute
