Dermatology MCQ 7 Medical Exam Questions With Answers

Dermatology MCQ 7 Exam Questions With Answers And Detailed Explanations

A 39-year-old female presents with red target lesion confined to the hands and is diagnosed with erythema multiforme. Which of the following could be the cause?

A. Cytomegalovirus infection

B. Sulphonamides ✅

C. Langerhan's cells histiocytosis

D. Group B streptococci

E. Ureaplasma urealyticum

Question Explanation:

Potential causes of erythema multiforme include:

1. Infections

Viruses: herpes simplex 1 and 2, hepatitis B, Epstein-Barr virus (EBV), enteroviruses

Small agents: Mycoplasma pneumonia

Bacteria: Group A Streptococcus, eosina

Other: Mycobacterium tuberculosis, Histoplasma, coccidioides.

2. Neoplasia

→ Leukemia

Lymphoma.

3. Antibiotics

Penicillins, sulphonamides, isoniazid, tetracycline.

 4. Anticonvulsants

 Phenytoin, phenobarbitone, carbamazepine.

5. Other

• Aspirin
• Radiation therapy
• Etoposide
• NSAIDS
• Sunlight
• Pregnancy.
  
  

Dysphagia, hard calcified nodules in the fingers, and cold hands are present for several years in a 40-year-old lady. Examination revealed calcified nodules, sclerodactyly, and facial telangiectasia. Which one of the antibodies is most likely to be found in blood?

A. Anticardiolipin

B. Anti-DNA antibodies

C. Antimitochondrial

D. Anticentromere ✅

E. Anti-endomysial

Question Explanation:

This patient has CREST syndrome which consists of calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly and telangiectasia. It is a limited form of scleroderma with less involvement of internal organ and is better referred to as "cutaneous limited systemic Sclerosis".

Which one of the following is a recognized feature of psoriasis?

A. Angular stomatitis

B. Koilonychia

C. Nail dystrophy ✅

D. Loss of hair

E. Response to Chloroquine

Question Explanation:

Fingernails and toenails are frequently affected (psoriatic nail dystrophy) and can be seen as an isolated symptom. Psoriasis is associated with a dermopathy and arthropathy which may range from mild distal interphalangeal joint involvement with nail pitting to severe arthritis mutilans. A Koebner phenomenon refers to the outbreak of a skin eruption following minor trauma and is a feature of psoriasis. Arthropathy may be associated with an anterior uveitis. Chloroquine may produce a severe attack of psoriasis.

A 76-year-old female presents with chronic leg ulceration which is a consequence of venous insufficiency. Which one of the following is the most appropriate management?

A. Appropriate systemic antibiotic in preparation for skin grafting

B. Improve the venous return by limb elevation

C. Sclerotherapy @

D. Vein surgery exclusion of neoplasm by skin biopsy

E. Compression bandaging ✅

Question Explanation:

Venous ulcers are secondary to venous stasis and chronic stretching vessel of the vein walls of the superficial veins. These eventually become thinner and ulcerate. The only treatment shown in studies to be beneficial for this condition would be to compress the superficial venous using a four-layer compression bandage. The patient should always have their Doppler's and ABPI (ankle brachial pulse index) prior to compression. This should be greater than 1.

Regarding treatment of psoriasis, which of the following statements is correct?

A. Etanercept is not effective in psoriatic arthritis

B. Psoralen is related to increased risk of squamous cell carcinoma ✅

C. PUVA is ineffective

D. Retinoids are the most useful monotherapy in psoriatic patients

E. Vitamin D analogues are associated with cutaneous atrophy

Question Explanation:

Psoralen and ultraviolet light (PUVA) is an effective treatment for psoriasis, but has been related to increased risk of squamous cell carcinoma, and possibly malignant melanoma.

Retinoids are most effective in combination therapy, especially with ultraviolet B (UVB) phototherapy and PUVA. Part of the attraction of vitamin D analogues over steroids is that they do not cause cutaneous atrophy, whereas steroids do. The recombinant tumour necrosis factor and receptor fusion protein, etanercept, has demonstrated considerable beneficial effects on psoriatic arthropathy in placebo controlled, double blind studies. Infliximab is associated with tuberculosis, by reactivation of latent disease. Thus it is advised that patients who are to be treated with infliximab are tuberculin tested, and if required, receive chest radiography.

Sunlight aggravates, which of the following lesion?

A. Pseudoxanthoma elasticum

B. Rosacea ✅

C. Acute intermittent porphyria >

D. Acne vulgaris

E. Psoriasis

Question Explanation:

Exacerbation or localisation of other dermatoses is characteristic of:

Rosacea

Pellagra

Hartnup's disease

Lupus erythematosus

Darier's disease

.Scleroderma

Actinic lichen planus

Lymphocytoma

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