MCQs:Dermatology

 

 

A 36 year old factory worker developed itchy, annular scaly plaques in both groins. Application of a corticosteroid ointment led to temporary relief but the plaques continued to extend at the periphery. The most likely diagnosis is:
A. Erythema annulare centrifugum
B. Granuloma annulare
C. Annular lichen planus
D. Tinea cruris

 

Correct answer : D. Tinea cruris
Tinea cruris is characterised by itchy, annular scaly plaques in both groins. There is central clearing and advancement at the periphery.

 

An 8 year old boy from Bihar presents with a 6 months history of an ill defined, hypopigmented slightly atrophic macule on the face. The most likely diagnosis is:
A. Pityriasis alba
B. Indeterminate leprosy
C. Morphea
D. Calcium deficiency

Correct answer : B. Indeterminate leprosy
Bihar is a known endemic region for leprosy.

 

All of the following drugs are effective in the treatment of pityriasis versicolor except:
A. Selenium sulphide
B. Ketoconazole
C. Griseofulvin
D. Clotrimazole

Correct answer : C. Griseofulvin
Griseofulvin is used in the treatment of dermatophyte infections.

 

 

A 16 year-old boy presented with asymptomatic, multiple, erythematous, annular lesions with a collarette of scales at the periphery of the lesions present on the trunk. The most likely diagnosis is:
A. Pityriasis versicolor
B. Pityriasis alba
C. Pityriasis rosea
D. Pityriasis rubra pilaris

Correct answer : C. Pityriasis rosea
The classical lesions of pityriasis rosea are described in the question.

 

In which of the following conditions Parakeratosis most frequently occurs?
A. Actinic keratoses
B. Seborrheic keratoses
C. Molluscum contagiosum
D. Basal cell carcinoma

Correct answer : A. Actinic keratoses
Parakeratosis refers to the persistance of cellular nuclei in the stratum corneum of skin.

 

 

A 6 month old infant had itchy erythematous papules and exudative lesions on the scalp, face, groins and axillae for one month. She also had vesicular lesions on the palms. The most likely diagnosis is:
A. Congenital shypilis
B. Seborrheic dermatitis
C. Scabies
D. Psoriasis

 

Correct answer : C. Scabies

 

A 45 year old farmer has itchy erythematous papular lesions on face, neck, ‘V‘ area of chest, dorsum of hands and forearms for 3 years. The lesions are more severe in summer and improve by 75% in winter. The most appropriate test to diagnose the condition would be:
A. Skin biopsy
B. Estimation of IgE levels in blood
C. Patch test
D. Intradermal prick test

 

Correct answer : C. Patch test
The history is suggestive of photodermatitis. Patch test is used for diagnosis of photodermatitis.
Patch test (photopatch test) : Here, 2 patches containing photosensitising material …

 

A 24-year old unmarried woman has multiple nodular, cystic, pustular and comedonal lesions on face, upper back and shoulders for 2 years. The drug of choice for her treatment would be:
A. Acitretin
B. Isotretinoin
C. Doxycycline
D. Azithromycin

 

Correct answer : B. Isotretinoin
The clinical picture is diagnostic of acne vulgaris. Isotretinoin is used in severe intractable acne.

 

Pterygium of nail is characteristically seen in:
A. Lichen planus
B. Psoriasis
C. Tinea unguium
D. Alopecia areata

Correct answer : A. Lichen planus

 

Air borne contact dermatitis can be diagnosed by:
a) Skin biopsy
b) Patch test
c) Prick test
d) Estimation of serum IgE levels

Correct answer : b) Patch test
In patch test, the suspected allergens are applied on the back of the patient under separate patches for 48 hours. The presence of dermatitis is then looked for.

 

The main cytokine, involved in erythema nodusum leprosum (ENL) reaction is:
a) Interleukin—2
b) Interferon-gamma
c) Tumor necrosis factor—alpha
d) Macrophage colony stimulating factor

 

Correct answer : c) Tumor necrosis factor—alpha

 

The following drug is not used for the treatment of type II lepra reaction:
a) Chloroquin
b) Thalidomide
c) Cyclosporine
d) Corticosteroids

Correct answer : c) Cyclosporine
Drugs used in treatment of type II lepra reaction are :

NSAID’s
Thalidomide
Chloroquine
Clofazimine
Corticosteroids
Parenteral antimony

 

 

Ivermectin in indicated in the treatment of
a) Syphilis
b) Scabies
c) Tuberculosis
d) Dermatophytosis

 

Correct answer : b) Scabies
Ivermectin the only orally effective treatment scabies.

 

Max. Joseph’s space is a histopathological feature of:
a) Psoriasis vulgaris
b) Lichen planus
c) Pityriasis rosea
d) Parapsoriasis

 

Correct answer : b) Lichen planus

 

‘Chancre redux’ is a clinical feature of:
a) Early relapsing syphlis
b) Late syphilis
c) Chancroid
d) Recurrent herpes simplex infection

Correct answer : a) Early relapsing syphilis

 

 True regarding Pityriasis Rosea is:
a) Self limiting
b) Chronic relapsing
c) Life threatening infection
d) Caused by dermatophytes

Correct answer : a) Self limiting
Pityriasis Rosea is a self limiting disease. Herald patch is the characteristic lesion.

 

 

Tuberculids are seen in
a) Lupus vulgaris
b) Scrofuloderma
c) Lichen scrofulosorum
d) Erythema nodosum

Correct answer : c) Lichen scrofulosorum

 

A 3 year old child has eczematous dermatitis on extensor surfaces, His mother has a history of Bronchial asthma. Diagnosis should be
a) Atopic dermatitis
b) Contact dermatitis
c) Seborrhic demiatitis
d) lnfantile eczematous dermatitis

Correct answer : a) Atopic dermatitis

 

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A 22 year old presents with itchy purple papules on his wrists and fingers and in his mouth with overlying white reticulate appearance. Which of the following is the most likely diagnosis? 

Lichen Planus	correct answer
Atopic dermatitis
Dermatitis Herpetiformis
Psoriasis
Reiters syndrome

 Explanation:

Lichen planus is the most likely diagnosis which presents with very itchy, small and shiny, flat topped purplish papules with an overlying network of fine white lines. It normally presents on the flexural surfaces of the knees, elbows, ankles and wrists and often affecting the mucous membranes especially the mouth. Koebners phenomenon is present. Psoriasis does not normally lead to the lesions described nor do the other options. 

 

A 40 year old male presents with arthralgia and syncopal episodes. An ECG reveals complete heart block. He returned from a hill walking holiday 3 months ago and has noticed an annular, indurated erythematous areas on his legs. What is the most likely diagnosis?

Lyme disease	correct answer
SLE
Tuberculosis
Psoriasis
Granuloma annulare

Explanation:

The rash described is characteristic of erythema chronicum migrans which is caused by Borrelia burgdorferi, a spirochaete leading to Lyme disease and is transmitted by the ixodid tick. It can lead to arthralgia and can lead to cardiac abnormalities such as heart block and can lead to neurological features such as cranial nerve palsies. For diagnosis, serology is required either in serum or CSF. 

 

A five year old boy is brought to the GP after noticing lesions on his neck and trunk. On examination there are several smooth, elevated, reddish papules with a central punctum. What is the most likely diagnosis?

Molluscum Contagiosum	correct answer
Warts
Lichen Planus
Herpes Simplex virus
Spitz Naevus

Explanation:

The most likely diagnosis is molluscum contagiosum. It is caused by the pox virus and is spread by direct contact. It is more common in children. It commonly affects the face, neck and trunk. The key to the diagnosis is the central punctum. This differentiates it from warts. Lichen planus tends to occur on wrists and mucous membranes and has a fine white reticulate layer.

 

A 52 year old female has developed a rash on her hands, feet which is gradually spreading centrally, predominantly on the extensor surfaces. She has been unwell for a few days before with a cold and the rash developed suddenly. On examination there is numerous circular lesions approximately 2cm in diameter which have a purpuric or pale centre. She states that new lesions develop whenever if there is any trauma to a site. Which of the following is most commonly associated with the development of these skin lesions?

Herpes simplex virus	correct answer
Herpes Zoster virus
Mycoplasma pneumoniae
Tuberculosis
Lymphoma

Explanation:

The classical target lesions described are most likely to be due to erythema multiforme. This can often be preceded by URTI symptoms and people can be very unwell with high fever. When the mucosa is severely involved this is known as Steven's Johnson Syndrome. It is associated most commonly with herpes simplex infection and also with drug reactions, other infective organisms such as mycoplasma infection and some connective tissue diseases. It is also associated with certain haematological malignancies such as leukaemia, Myeloma and non-Hodgkin's Lymphoma. 

 

A 32 year old gentleman has been undergoing topical treatment for psoriasis for some time. He presents as he has noticed patches of skin which appear thin and lax and which are hypopigmented and shiny with prominent blood vessels. What is the most likely cause of this?

Topical steroid use	correct answer
Topical tar based cream
Advanced psoriatic plaques
Topical vitamin A analogue
Dithranol

Explanation:

The lesions described are typical of skin atrophy secondary to repeated topical steroid use. Dithranol is more difficult to use and is often only applied in a hospital setting. Dithranol, topical vitamin A and tar based creams can be irritant but do not lead to atrophy.

 

A 16 year old female presents with a purpuric rash on her buttocks, arms and back of legs. The lesions began as erythematous macules. She is complaining of arthralgia and abdominal pain with some bloody diarrhoea. She had a cold about one week ago. On dipstick of urine there is evidence of proteinuria and microscopic haematuria. Given the most likely diagnosis, what is the likeliest outcome?

 

Full recovery	correct answer
Recurring episodes
Chronic kidney disease
Acute renal failure without full recovery
Steroids required for full recovery

Explanation:

Henoch Schonlein purpura is the most likely diagnosis. It is a vasculitis and presents in children with a higher incidence in males. It leads to a purpuric rash on ulnar side of arms, buttocks and back of legs which begin as erythematous macules. A URTI can precede it's development. Arthralgia, abdominal pain and diarrhoea are common features. It leas to eosinophilia and raised IgA. There is evidence of glomerulonephritis and sometimes a nephrotic syndrome can develop. In the majority of cases HSP is self limiting and there is full recovery. In a minority there is recurring episodes. It is rare in children for end stage renal failure to develop. It is rare in adults but when is does it is more likely to be severe and cause permanent kidney damage. Steroids are useful in severe disease and are useful for relief of arthralgia and GI symptoms.

 

A 20 year old male presents with a rash to his GP. It is predominantly over his trunk and there is multiple papules and red scaly plaques with some looking like rain drops. These are itchy. He has recently been unwell with presumed strep. throat. He has recently had sex with a new partner. What is the most likely diagnosis?

Guttate psoriasis	correct answer
Secondary syphilis
Toxic Epidermal Necrolysis
Pityriasis
Reiters syndrome

Explanation:

The history and clinical findings are indicative of Guttate Psoriasis. Secondary syphilis can lead to a similar rash however there is no evidence of primary infection. Reiters Syndrome is a triad of arthritis, urethritis and conjunctivis and a rash which classically affects the palms and soles. It is often secondary to gonococcal infection.

 

 

A 35 year old male presents with bald patches. These are well defined and there is no evidence of scarring. There is some broken hairs surrounding these areas. What is the most likely diagnosis?

Alopecia areata	correct answer
Discoid lupus
Telogen effluvium
Psoriasis
Tinea capitis

Explanation:

Alopecia areata leads to well defined areas of baldness with no scarring. Broken hairs may be seen at the edge which can be depigmented. Nail dystrophy in the form of pitting may be observed. It is autoimmune and associated with other autoimmune disorders. There may be a genetic component. Discoid Lupus leads to baldness but there is evidence of inflammation and scarring, scaling and follicular plugging and hair does not regrow unlike in alopecia where is usually fully recover in about 18 months. Telogen effluvium is a generalised, diffuse hair loss often seen in pregnancy but also in stress and malnutrition. Tinea capitis would show scaling and microscopic examination should be done to exclude this.

 

 A 22 year old presents with a rash. On examination there are small salmon pink papules with a fine scale which are drop like on her trunk and proximal arm and legs. She had suffered from tonsillitis two weeks previously. What is the most likely diagnosis?

Guttate Psoriasis	correct answer
Dermatitis
Lichen Planus
Secondary Syphillis
Pityriasis Rosea

Explanation:

The history and clinical features are highly suggestive of Guttate psoriasis. It is mostly associated with streptococcal infection but is also associated with stress, trauma and drugs such as antimalarials, lithium, NSAIDs and betablockers. Lichen planus tends to affect flexor surfaces and mucous membranes, is intensely itchy and more violaceous in colour. Secondary syphillis would typically be associated with other features and affects the palms and soles. Pityriasis rosea classically has a "Christmas tree distribution" and has a ring of scale and is itchy.

  

A70 year old presents with a lesion on his cheek. The lesion has a raised, pearly border and there is telangiectasia on the surface of the lesion. What is the most likely diagnosis?

Basal Cell Carcinoma	correct answer
Squamous Cell Carcinoma
Actinic Keratosis
Wart
Melanoma

Explanation:

The lesion described is typical of a nodular basal cell carcinoma. These present on sun exposed skin. Superficial BCCs more often present on the body but differ in that instead of telangiectasia they appear scaling black with a pearly white raised border. Excision surgery is the treatment of choice.

 

A 29 year old female presents to her GP. She has noticed dandruff and a rash on her face. On examination there is evidence of areas of erythema with fine scaling over her nasal bridge, around her nasolabial fold and eyebrows and ears and there is evidence of fine scaling on the scalp. What is the most likely diagnosis?

Seborrhoeic Dermatitis	correct answer
Psosriasis
Rosacea
Eczema
Pityriasis Capitis

 

 Which of the following is the most appropriate initial treatment?

Topical Ketoconazole	correct answer
Topical steroids
Oral Fluconazole
Oral Steroids
PUVA

Explanation:

The clinical features described are characteristic of Seborrhoeic dermatitis. It is thought to be caused by an inflammatory reaction to the yeast Malassezia. Typically the face and scalps is affected as described here however other areas which can be involved include the sternum and upper back and the skin flexures. Treatment includes topical ketoconazole including shampoo and topical steroids intermittently. More severe disease may be treated with oral antifungals and UV light treatment.

A 27 year old soldier has just returned from Afghanistan. He has been sent to the dermatology due to a lesion on his right forearm. He states that this began as a small red patch which them increased in size. On examination there is an erythematous raised lesion on his right forearm which has ulcerated and has crusted over. He is otherwise well. Which of the following is the most likely diagnosis?

Cutaneous Leishmaniasis	correct answer
Mucocutaneous Leishmaniasis
Psoriasis
Eczema
Squamous Cell Carcinoma

Explanation:

Given where the patient has travelled to and the description of the lesion, the most likely diagnosis is cutaneous leishmaniasis. Cutaneous Leishmaniasis is caused by old world protozoa such as L. tropica or Infantum or new world protozoa such as L. Mexicana. This leads to the lesion described. Mucocutaneous leishmaniasis is a risk in new world leishmaniasis. Visceral leishmaniasis is caused by L. Donovani or Chagasi and affects the reticuloendothelial system and leads to anaemia and hepatosplenomegaly.

 

What disorder would you most commonly associate with Stevens Johnson syndrome?

Herpes simplex infection	correct answer
Sarcoidosis
Infective Endocarditis
Streptococcal infection
Penicillin Use

Explanation:

Herpes simplex infection is most commonly associated with Stevens Johnson syndrome. It is also associated with mycoplasma pneumoniae, certain drugs such as penicillin and anticonvulsants and with haematological malignancies.

 

 A 28 year old soldier presents with an itchy rash. He is itchy in his finger webs, wrists and groin and there is evidence of excoriation in these areas. What is the most likely diagnosis?

Sarcoptes scabiei infection	correct answer
Psoriasis
Lichen Planus
Tinea Corporis Contact dermatitis

Explanation:

 The history is indicative of scabies. AS well as the wrist, finger webs and groin other areas commonly affected are elbows and perineum. Sometimes burrow holes can be observed and mites extracted with a needle. The whole body must be treated with topical preparations such as gamma benzene hexachloride or benzyl benzoate. Due to the lack of the classical rashes in the other diagnoses and the areas affected the other diagnoses are less likely.

 

A 60 year old gentleman presents with a mole on the sole of his foot. On examination there is evidence of a 1.5cm mole with border irregularity and a halo surrounding it. What is the most likely diagnosis?

Acral lentiginous melanoma	correct answer
Periungual melanoma
Lentigo maligna melanoma
Nodular melanoma
Superficial spreading melanoma

Explanation:

The most likely diagnosis is acral lentiginous melanoma which is observed on the sole of the foot. It is often surrounded by a halo of paler skin. Periungual melanoma is not the diagnosis as it occurs in the nail bed. Lentigo maligna melanoma is a large flat area of pigmentation. Nodular melanoma is very aggressive and is nodular and can be depigmented and does not occur on the sole.

 

 A patient with ulcerative colitis develops several necrotic ulcers on her legs. How do you manage these?

Prednisolone	correct answer
Antibiotics
Angiogram
Local application of silver nitrate
Dressings alone

Explanation:

 The likely diagnosis is pyoderma gangrenosum and prednisolone is the most appropriate from this list for management.

 

A 14 year old girl presents with moderate acne and pustules affecting the face, back and chest. How would you manage this case?

Oral tetracycline for three months	correct answer
Topical tretinoin
Topical erythromycin
Roaccutane
Dianette

Explanation:

Due to the fact this patient has features of moderate acne then oral tetracycline for three months is the most appropriate treatment. Erythromycin is an alternative. This is a second line treatment and mild acne is normally treated with topical agents such as topical antibiotics, keratolytics or topical retinoids. Dianette is another option but is also used as a contraceptive and has other implications. Roaccutane is an oral retinoid and is a third line therapy only prescribed by dermatologists and with certain inclusion criteria due to the teratogenicity.