Dermatology Prometric exam questions

The Dermatology exam in every GCC country

From each regulator's own exam pages; anything a regulator does not publish says so. Assessment mode also depends on your licence title, so confirm your route on your eligibility notice.

12 worked Dermatology practice questions

Original exam-style questions from the bank, spread across the blueprint domains. They are not real or recalled exam questions. Try each one, then open the answer for the rationale and reference. None of them appear in the free mock exam, so reading them will not spoil it.

1. Question 1 · Papulosquamous and Eczematous Dermatoses

   A 29-year-old woman at 32 weeks gestation, with no personal history of psoriasis, develops fever, malaise and erythematous plaques in the groins and axillae fringed by tiny sterile pustules that extend centrifugally. Serum calcium is 1.95 mmol/L and albumin is low. What is the most likely diagnosis?

   1. APemphigoid gestationis
   2. BImpetigo herpetiformis (generalised pustular psoriasis of pregnancy)
   3. CAcute generalised exanthematous pustulosis
   4. DPolymorphic eruption of pregnancy
   Show answer and explanation

   Correct answer: B. Impetigo herpetiformis (generalised pustular psoriasis of pregnancy)

   Impetigo herpetiformis is generalised pustular psoriasis occurring in pregnancy, typically in the late second or third trimester, beginning in flexures with expanding rings of sterile pustules and accompanied by fever, hypocalcaemia and hypoalbuminaemia, with a risk of placental insufficiency requiring close fetal monitoring. Pemphigoid gestationis produces periumbilical urticarial plaques and tense bullae with linear C3 on direct immunofluorescence, AGEP follows a culprit drug within days, and polymorphic eruption of pregnancy is an itchy non-pustular eruption in abdominal striae without systemic upset.

   Reference: Ambros-Rudolph, Obstetric Dermatology, in Bolognia Dermatology, 5th ed., 2024; Namazi & Dadkhahfar, Dermatol Res Pract, 2018

2. Question 2 · Urticaria, Erythemas, Drug Eruptions, Purpura and Cutaneous Vasculitis

   A patient of Han Chinese ancestry is to start carbamazepine for trigeminal neuralgia. Which pharmacogenetic test should be considered before prescribing, and why?

   1. AHLA-B*58:01, because it predicts allopurinol-induced severe cutaneous adverse reactions
   2. BTPMT genotype, because carbamazepine is metabolised by thiopurine methyltransferase
   3. CHLA-A*31:01, because it predicts carbamazepine-induced SJS/TEN in all ethnic groups equally
   4. DHLA-B*15:02, because it is strongly associated with carbamazepine-induced SJS/TEN in Southeast Asian populations
   Show answer and explanation

   Correct answer: D. HLA-B*15:02, because it is strongly associated with carbamazepine-induced SJS/TEN in Southeast Asian populations

   HLA-B*15:02 carriage confers a markedly increased risk of carbamazepine-induced SJS/TEN in Han Chinese, Thai, Malay and other Southeast Asian populations, and screening before initiation is recommended by regulators and CPIC. HLA-B*58:01 relates to allopurinol; HLA-A*31:01 is associated mainly with carbamazepine hypersensitivity syndrome/DRESS and maculopapular eruption in European and Japanese populations rather than being a universal SJS/TEN marker; TPMT is relevant to thiopurines, not carbamazepine.

   Reference: CPIC Guideline for HLA Genotype and Use of Carbamazepine and Oxcarbazepine (2017 update), Clin Pharmacol Ther

3. Question 3 · Basic Science, Skin Biology, Cutaneous Immunology and Dermatopathology

   A 9-year-old child has blistering from birth at sites of friction, healing with atrophic scars and milia, dystrophic nail loss and progressive pseudosyndactyly of the hands. Genetic testing identifies biallelic COL7A1 mutations. Which ultrastructural component of the dermal-epidermal junction is defective?

   1. AKeratin 5/14 intermediate filaments within basal keratinocytes
   2. BAnchoring fibrils extending from the lamina densa into the papillary dermis
   3. CThe inner hemidesmosomal plaque containing plectin and BP230
   4. DAnchoring filaments crossing the lamina lucida
   Show answer and explanation

   Correct answer: B. Anchoring fibrils extending from the lamina densa into the papillary dermis

   COL7A1 encodes type VII collagen, the sole constituent of anchoring fibrils that loop from the lamina densa into the papillary dermis; their loss causes recessive dystrophic epidermolysis bullosa with sub-lamina densa cleavage, scarring, milia and mitten deformity. Keratin 5/14 defects cause epidermolysis bullosa simplex with intrabasal cleavage and minimal scarring. Plectin/BP230 plaque defects also cause simplex-type disease, and laminin-332 anchoring filament defects cause junctional EB with cleavage in the lamina lucida.

   Reference: Has C et al. Consensus reclassification of inherited epidermolysis bullosa. Br J Dermatol, 2020

4. Question 4 · Pediatric Dermatology and Genodermatoses

   A newborn has a 2 cm well-circumscribed, hairless, membranous defect on the vertex of the scalp, present at birth and surrounded by a ring of long dark coarse hair. What is the most appropriate next step?

   1. AImmediate surgical excision and primary closure in the first week of life
   2. BImaging of the underlying skull and brain (ultrasound and/or MRI) to exclude cranial dysraphism or an underlying encephalocele before any manipulation
   3. CReassurance alone, as all lesions of this type heal without complication
   4. DEmpirical intravenous antibiotics for suspected congenital infection
   Show answer and explanation

   Correct answer: B. Imaging of the underlying skull and brain (ultrasound and/or MRI) to exclude cranial dysraphism or an underlying encephalocele before any manipulation

   The hair collar sign, a ring of coarse dark hair encircling a membranous scalp defect, is a marker of an underlying cranial neural tube closure defect such as a meningocele, encephalocele or heterotopic brain tissue, and imaging must precede any biopsy or excision to avoid catastrophic complications including CSF leak and meningitis. Simple non-membranous aplasia cutis congenita usually heals with an atrophic scar and can be managed conservatively, but this is the subgroup that requires investigation. Antibiotics are not indicated in the absence of infection.

   Reference: Drolet BA et al., 'Hair collar sign': marker for cranial dysraphism, Pediatrics (1995); Paller & Mancini, Hurwitz Clinical Pediatric Dermatology, 6th ed. (2022)

5. Question 5 · Hair, Nail, Adnexal and Mucous Membrane Disorders

   A 45-year-old woman with a 2-year history of progressive vertex hair loss is scheduled for a scalp biopsy to distinguish a non-scarring from a scarring alopecia. Which biopsy approach gives the most information for this indication?

   1. AA single 2 mm punch biopsy from the centre of the bald vertex, sectioned vertically
   2. BA shave biopsy of the vertex including only epidermis and papillary dermis
   3. CAn elliptical biopsy of clinically normal occipital scalp
   4. DA 4 mm punch biopsy taken from active affected scalp, oriented parallel to the hair shafts, with horizontal (transverse) sectioning
   Show answer and explanation

   Correct answer: D. A 4 mm punch biopsy taken from active affected scalp, oriented parallel to the hair shafts, with horizontal (transverse) sectioning

   A 4 mm punch angled parallel to the hair shafts and carried into subcutaneous fat captures whole follicular units, and horizontal sectioning allows counting of terminal and vellus follicles, the terminal:vellus ratio and follicular density, which is the key discriminator in alopecia. A 2 mm punch samples too few follicles, and end-stage bald skin shows only fibrous tracts without diagnostic information. A shave biopsy misses the bulbs in the subcutis, and biopsying uninvolved scalp will not show the pathology.

   Reference: British Association of Dermatologists guidelines for the management of alopecia areata (2022) and Sperling's Atlas of Hair Pathology with Clinical Correlation, 3rd ed. (2021)

6. Question 6 · Pigmentary Disorders and Photodermatoses

   Which statement most accurately distinguishes a photoallergic from a phototoxic drug reaction?

   1. APhototoxic reactions require previous sensitisation and can spread to covered skin, whereas photoallergic reactions occur on first exposure
   2. BPhototoxic reactions are typically eczematous and delayed by 24 to 48 hours, whereas photoallergic reactions look like exaggerated sunburn within hours
   3. CPhotoallergic reactions are cell-mediated, dose-independent, eczematous, delayed by 24 to 48 hours, may extend beyond sun-exposed skin, and are confirmed by photopatch testing
   4. DBoth types occur only with UVB and neither can be reproduced by testing
   Show answer and explanation

   Correct answer: C. Photoallergic reactions are cell-mediated, dose-independent, eczematous, delayed by 24 to 48 hours, may extend beyond sun-exposed skin, and are confirmed by photopatch testing

   Photoallergy is a type IV cell-mediated response to a photo-antigen: it requires prior sensitisation, is not dose-dependent, appears as delayed eczematous dermatitis 24 to 48 hours after exposure, may spread to covered skin, and is confirmed by photopatch testing. Phototoxicity is far commoner, needs no sensitisation, is dose-dependent, and produces an exaggerated sunburn with burning within minutes to hours confined to exposed skin, so the first two options invert the definitions. Most clinically important photosensitisers, including doxycycline, thiazides, amiodarone, voriconazole and non-steroidal anti-inflammatory drugs, act mainly through UVA, and reactions can be reproduced by phototesting or photopatch testing.

   Reference: Fitzpatrick's Dermatology in General Medicine, 9th edition, 2019; Rook's Textbook of Dermatology, 9th edition, 2016

7. Question 7 · Dermatologic Emergencies, Patient Safety, Professionalism and Ethics

   The adult son of a 70-year-old woman with newly diagnosed metastatic melanoma asks the dermatologist not to tell his mother the diagnosis, saying it is culturally inappropriate and will destroy her hope. The patient has full capacity and has previously asked to be kept informed. What is the most appropriate course?

   1. AComply with the family's wish, as family-centred decision-making takes precedence in the region
   2. BExplore the son's concerns, then sensitively ask the patient herself how much she wishes to know and who she wants involved, and follow her stated preference
   3. CTell the son the family has no standing and disclose the diagnosis to the patient in his presence without further discussion
   4. DDisclose only to the son and document that the patient was deemed too fragile to be told
   Show answer and explanation

   Correct answer: B. Explore the son's concerns, then sensitively ask the patient herself how much she wishes to know and who she wants involved, and follow her stated preference

   The competent patient determines the flow of her own information, and the ethically robust solution is to acknowledge the family's protective motive while directly ascertaining the patient's own preference about disclosure and family involvement - a patient may validly delegate information to family, but that must be her choice. Simply complying with the son colludes in deception against her expressed wish to be informed. Dismissing the family confrontationally damages the therapeutic alliance without benefit. Disclosing only to the son and labelling her fragile is unjustified paternalism and a confidentiality breach.

   Reference: Beauchamp and Childress, Principles of Biomedical Ethics, 8th ed. (2019); General Medical Council, Decision Making and Consent (2020)

8. Question 8 · Cutaneous Infections, Infestations, Bites and Sexually Transmitted Infections

   A 52-year-old man admitted in diabetic ketoacidosis develops unilateral facial pain, periorbital swelling, nasal discharge and a black necrotic eschar on the hard palate and nasal turbinates. Biopsy shows broad, ribbon-like, pauciseptate hyphae with wide-angle branching and angioinvasion. What is the most appropriate management?

   1. AUrgent surgical debridement plus intravenous liposomal amphotericin B, with aggressive correction of the ketoacidosis
   2. BOral voriconazole alone
   3. COral fluconazole with topical antiseptic packing
   4. DIntravenous ceftriaxone and metronidazole
   Show answer and explanation

   Correct answer: A. Urgent surgical debridement plus intravenous liposomal amphotericin B, with aggressive correction of the ketoacidosis

   Broad pauciseptate ribbon-like hyphae with angioinvasion in a ketoacidotic patient indicate rhino-orbito-cerebral mucormycosis, where survival depends on early surgical debridement, first-line liposomal amphotericin B and reversal of the underlying acidosis and hyperglycaemia. Voriconazole has no reliable activity against Mucorales and its use has been associated with breakthrough mucormycosis; fluconazole likewise lacks activity. Antibacterial therapy alone does not address the fungal angioinvasion.

   Reference: ECMM/MSG Global Guideline for the Diagnosis and Management of Mucormycosis (Cornely et al., Lancet Infect Dis, 2019)

9. Question 9 · Cutaneous Neoplasms and Skin Cancer

   Four patients each have a single, clinically node-negative cutaneous squamous cell carcinoma. Which feature confers the highest risk of local recurrence and nodal metastasis and therefore warrants the most aggressive management and staging?

   1. AA 1.0 cm well-differentiated tumour on the forearm with 2 mm depth of invasion
   2. BA 1.4 cm well-differentiated tumour on the back with no perineural involvement
   3. CHistological perineural invasion of a named nerve measuring 0.15 mm in calibre
   4. DA 0.8 cm moderately differentiated tumour of the cheek confined to the papillary dermis
   Show answer and explanation

   Correct answer: C. Histological perineural invasion of a named nerve measuring 0.15 mm in calibre

   Large-calibre perineural invasion (nerves 0.1 mm or greater in diameter) is a major high-risk staging factor in both the Brigham and Women's Hospital and AJCC 8th edition systems and is strongly associated with local recurrence, nodal spread and disease-specific death, mandating wide or Mohs excision, nodal imaging and consideration of adjuvant radiotherapy. Small, well or moderately differentiated tumours with limited depth on the trunk, limbs or cheek without other adverse features are low-risk and are adequately treated by standard excision.

   Reference: AJCC Cancer Staging Manual, 8th ed. (2017); Karia PS et al., BWH tumour staging (JCO, 2014); NCCN Squamous Cell Skin Cancer (2024)

10. Question 10 · Connective Tissue Disease, Dermal, Subcutaneous, Metabolic and Systemic Skin Disease

    In the 2019 EULAR/ACR classification criteria for systemic lupus erythematosus, which requirement must be satisfied before the weighted additive criteria are counted?

    1. AA positive anti-double-stranded DNA antibody
    2. BAn antinuclear antibody titre of at least 1:80 on HEp-2 cells or an equivalent positive test
    3. CBiopsy-proven lupus nephritis
    4. DLow serum C3 and C4
    Show answer and explanation

    Correct answer: B. An antinuclear antibody titre of at least 1:80 on HEp-2 cells or an equivalent positive test

    The 2019 EULAR/ACR criteria use a positive ANA at a titre of at least 1:80 on HEp-2 cells (or an equivalent positive assay) as the obligatory entry criterion; only then are the weighted clinical and immunological domain items summed, with a score of 10 or more and at least one clinical criterion classifying the patient. Anti-dsDNA, low complement and biopsy-proven nephritis are individual weighted items, not entry requirements, and lupus nephritis class III/IV alone scores 10 but still needs the ANA entry criterion.

    Reference: Aringer M et al., 2019 EULAR/ACR Classification Criteria for Systemic Lupus Erythematosus, Arthritis & Rheumatology / Annals of the Rheumatic Diseases (2019)

11. Question 11 · Procedural, Surgical, Laser and Cosmetic Dermatology

    Shortly after a large-volume field infiltration of local anaesthetic, a patient complains of perioral numbness, metallic taste and tinnitus, then becomes agitated and has a generalised tonic-clonic seizure. Injection is stopped, the airway is supported with 100% oxygen and a benzodiazepine is given. Which additional intervention is most specific for this condition?

    1. AIntravenous 20% lipid emulsion bolus followed by an infusion
    2. BIntravenous flumazenil
    3. CIntravenous methylene blue 1 mg/kg
    4. DIntramuscular adrenaline 0.5 mg
    Show answer and explanation

    Correct answer: A. Intravenous 20% lipid emulsion bolus followed by an infusion

    This is local anaesthetic systemic toxicity, and after airway and seizure control the specific antidote is intravenous 20% lipid emulsion, which creates a lipid sink and supports myocardial function. Flumazenil reverses benzodiazepines and would worsen seizure control, methylene blue treats methaemoglobinaemia (a risk with prilocaine/benzocaine, not this presentation), and intramuscular adrenaline treats anaphylaxis, which would present with urticaria, bronchospasm and hypotension rather than prodromal neurological excitation.

    Reference: American Society of Regional Anesthesia and Pain Medicine (ASRA) Practice Advisory on Local Anesthetic Systemic Toxicity, 2018 update

12. Question 12 · Hair, Nail, Adnexal and Mucous Membrane Disorders

    Culture from a patient with confirmed toenail onychomycosis grows Trichophyton rubrum. He takes no regular medications and has normal baseline liver enzymes. Which regimen is the most appropriate first-line systemic therapy?

    1. ATerbinafine 250 mg daily for 12 to 16 weeks with liver function monitoring
    2. BGriseofulvin 500 mg daily for 4 weeks
    3. CTopical amorolfine lacquer weekly alone for 12 weeks
    4. DOral ketoconazole 200 mg daily for 6 months
    Show answer and explanation

    Correct answer: A. Terbinafine 250 mg daily for 12 to 16 weeks with liver function monitoring

    Continuous terbinafine is the most effective and guideline-preferred systemic therapy for dermatophyte toenail onychomycosis, given for about 12 to 16 weeks with baseline and interval liver monitoring, since it is fungicidal against Trichophyton and persists in the nail plate after dosing stops. Griseofulvin requires 12 to 18 months for toenails with far lower cure rates. Topical lacquer monotherapy is reserved for superficial or limited distal disease without matrix involvement. Systemic ketoconazole is no longer used for dermatophyte infection because of hepatotoxicity and adrenal suppression.

    Reference: British Association of Dermatologists guidelines for the management of onychomycosis (2014); EMA restriction on oral ketoconazole (2013)

Dermatology reference books and guidelines

Every question in this bank names the textbook or guideline its answer rests on. These are the sources our Dermatology questions cite most often - the reading list to revise from alongside the bank.

Where your regulator publishes a reading list, use the editions it names. Exam questions are not taken from any one book.