Dermatology: AIIMS MAY 2013

Q-1. A middle aged male presents with multiple painful blisters on an erythematous base along the T3 dermatome on the trunk. Which of the following etiological agents is most likely to be implicated?
a) Pox virus
b) Varicella zoster
c) Herpes simplex virus
d) Human papilloma virus

Answer: Varicella zoster
Reactivation of varicella-zoster virus (VZV) that has remained dormant within dorsal root ganglia, often for decades after the patient’s initial exposure to the virus in the form of varicella (chickenpox), results in herpes zoster (shingles).
The pre-eruptive phase is characterized by sensory phenomena along one or more skin dermatomes.
The acute eruptive phase is marked by the following:
Patchy erythema, occasionally accompanied by induration, in the dermatomal area of involvement
Regional lymph-adenopathy
Grouped herpetiform vesicles developing on the erythematous base
Cutaneous findings that typically appears unilaterally, stopping abruptly at the midline of the limit of sensory coverage of the involved dermatome

Q-2. The Ridley-Jopling classification for leprosy is based on which of the following parameters?
a) Histopathological, clinical, bacteriological and immunological
b) Histopathological, clinical, bacteriological and therapeutic
c) Histopathological, bacteriological, epidemiological and therapeutic
d) Histopathological, bacteriological and epidemiological

Answer: Histopathological, clinical, bacteriological and immunological
The Ridley-Jopling classification for leprosy:
Tuberculoid (TT), borderline TT (BT), borderline (BB), borderline lepromatous (BL) and lepromatous (LL) Leprosy
Ridley–Jopling classification was based on clinical, histological and immunological differences (lepromin test) in the disease.

Q-3. A young male presents with painful ulcers on the mouth and glans penis with blurred vision and history of recurrent Epididymitis. Which of the following is the most probable diagnosis?
a) Behcet’s syndrome
b) Fabry’s disease
c) Epidermolysis bullosa
d) Oculo-cutaneous aphthous ulcer syndrome

Answer: Behcet’s syndrome
Behçet’s syndrome is classically characterized as a triad of symptoms that include recurring crops of mouth ulcers (aphthous ulcers, canker sores), genital ulcers, and inflammation of a specialized area around the pupil of the eye termed the uvea.
Behçet’s syndrome is diagnosed based on the finding of recurrent mouth ulcerations combined with any two of the following: eye inflammation, genital ulcerations, or skin abnormalities.
A special skin test called a pathergy test can also suggest Behçet’s syndrome.
This test consists of pricking the skin of the forearm with a sterile needle.
The test is called positive and suggests Behçet’s syndrome when the puncture causes a sterile red nodule or pustule that is greater than two millimeters in diameter at 24 to 48 hours after the test.

Q-4. Multiple, shiny, pinhead size papules on dorsal surface of hand, forearm & penis in young boy
a) Scabies
b) Lichen planus
c) Lichen nitidus
d) Molluscum contagiosum

Ans: Lichen nitidus
Lichen nitidus:
Lichen nitidus is a relatively rare, chronic skin eruption that is flat-topped, skin-colored micro-papules (Pinpoint to pinhead size). Lichen nitidus mainly affects children and young adults.
The most common sites of involvement are the trunk, flexor aspects of upper extremities, dorsal aspects of hands, and genitalia.
Lichen nitidus is usually an asymptomatic eruption; however, patients occasionally complain of pruritus.