Dermatology

Question 1

Differentiate Erythema Multiforme from Lyme Disease

Answer 1

Both EM and Lyme present with target lesion, joint pain and flu-like illness.

Erythema Multiforme - multiple target lesions
Erythema Migrans (seen in Lyme Disease) - single migrating target lesion

Causes:
Erythema Multiforme - caused by infection (HSV, Mycoplasma pneumonia) or drugs (like penicillin)

Question 2

Tender, erythematous, nodular lesions usually over the shin

What causes it?

Answer 2

Erythema Nodosum

-caused by Sarcoidosis, IBD, drugs

Question 3

Other term for polymorphic eruption of pregnancy

Answer 3

Pruritic urticarial papules and plaques of pregnancy

Question 4

Pruritic, urticaria-like, occurring during the last trimester, primiparous, starting as abdominal striae, no blisters, spares the umbilicus

Answer 4

PEP or PUPPP

Question 5

Other term for polymorphic eruption of pregnancy

Answer 5

Pruritic urticarial papules and plaques of pregnancy

Question 6

Pruritic, blistering lesions, develop in the peri-umbilical region
Diagnosis?
Management?

Answer 6

Pemphigoid gestationis

Oral corticosteroids

Question 7

Severe itchy rash; associated with celiac disease (loose fatty stools difficult to flush, IDA, vitamin B12 and folic acid deficiency)

Answer 7

Dermatitis herpetiformis

Question 8

Target lesion + history of camping or walking in the jungles
Type of Rash?
Diagnosis?
Causative agent?

Answer 8

Erythema migrans
Lyme disease
Borrelia burgdorferi

Question 9

Pink rings, barely raised, non-itchy + rheumatic fever

Rash diagosis?

Answer 9

Erythema marginatum

***Remember that EM is part of the major criteria in the diagnosis of RF

Question 10

Painful tender nodules over shin + history of TB or sarcoidosis or IBD (UC or CD) or penicillin

Answer 10

Erythema nodosum

Question 11

Pink rings, barely raised, non-itchy + rheumatic fever

Rash diagosis?

Answer 11

Erythema marginatum

***Remember that EM is part of the major criteria in the diagnosis of RF

Question 12

Target lesion + history of HSV, mycoplasma pneumonia, use of penicillin (amoxicillin)
Rash diagnosis?

Answer 12

Erythema Multiforme

Question 13

1st line treatment for impetigo

Answer 13

Topical H2O2 1%

Question 14

Patient presents with slapped cheek appearance sparing the nasolabial fold and the eyes
What type of erythema?
Diagnosis?
Management?

Answer 14

Erythema Infectiosum
Parvovirus B19
Rest and analgesia

Question 15

When should a patient with parvovirus B19 be excluded from school?

Answer 15

Once the rashes appear

Question 16

First line treatment for scabies

Answer 16

Topical Permethrin 5% (NOT 0.5%)
P5

***Remember P5, also permethrin is not contraindicated in pregnancy

Question 17

History of sore throat 2-4 weeks ago + tear drop scaly papules on the trunk and limbs
Diagnosis?
Management?

Answer 17

Guttate psoriasis

No treatment required / May also give topical steroids

Question 18

Histopath feature that would suggest bad prognosis of malignant melanoma

Answer 18

Depth of invasion (Breslow thickness)

Question 19

Features of a benign mole that would suggest it to be malignant melanoma

Answer 19

Diameter > 6mm

Varying color

Question 20

A lipoma has very rare chances of being malignant.
What features would make you think of liposarcoma?
What investigation of choice should you do to differentiate lipoma from liposarcoma?

Answer 20

Size > 5 cm, increasing in size, painful, deep anatomical location
Ultrasound

Question 21

First line treatment of eczema

Answer 21

Emolients

Question 22

History of camping or walking in jungles or parks + itchy rash at the same day.
Diagnosis?
Management?

Answer 22

Insect Bite

Oral antihistamines

Question 23

History of camping or walking in jungles or parks + annular rash 3-30 days later
Diagnosis?
Management?

Answer 23

Lyme disease

Oral doxycycline

Question 24

Mild topical steroids

Answer 24

Hydrocortisone acetate (0.5, 1 or 2.5%)

Question 25

Betamethasone can be used for moderate eczema or for severe eczema. Which concentration of betamethasone should be used for which?

Answer 25

Moderate eczema - 0.025%

Severe eczema - 0.1%

Question 26

Children younger than 5 years + fever with irritability and widespread redness of the skin + blister formation after 24-48 hours + Nikolsky sign
Diagnosis?
Management?

Answer 26

SSSS

Admit, F&E balance. Nutrition and analgesics. Flucloxacillin.

Question 27

Skin biopsy shows intraepidermal cleavage at the granular layer

Answer 27

SSSS

Question 28

Skin biopsy immunofluorescence shows IgG and C3 at the dermoepidermal junction

Answer 28

Bullous pemphigoid

Question 29

Mainstay of treatment for bullous pemphigoid

Answer 29

Oral corticosteroids

Question 30

Children with atopic eczema + rapidly progressing painful and itchy rash + PE: monomorphic punched-out erosions and ulcers which are oozing and crusting
Treatment?

Answer 30

Antivirals

This is eczema herpeticum caused by HSV1 and HSV2

Question 31

History of radiotherapy + ulcer with central depression and rolled edged

Answer 31

Basal cell carcinoma

Question 32

Treatment of minor paronychia

Answer 32

Fucidic acid

Question 33

Treatment of severe infection of paronychia

Answer 33

Flucloxacillin or Clarithromycin

***Remember FaronyChia

Question 34

Second line treatment for impetigo if first line has been given already?

Answer 34

Fucidic acid or Mupirocin

Question 35

Herald patch is a sign of what dermatologic condition?

Answer 35

Pityriasis rosea

Question 36

Raised edge pearly pink lesion with central depression or ulcer anywhere in the face

Answer 36

Basal cell CA