This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
[{'content': 'Auspitz sign is a feature of \nSelect and explain. \nA. Psoriasis, B. Lichen planus, C. Pityriasis alba, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: When psoriatic scales are completely scraped off, the basement membrane is exposed and is seen as moist red surface (membrane of Bulkeley) through which dilated capillaries can be seen as red spots.\nOn further scraping, these capillaries at the tip of elongated papillae are torn leading to multiple bleeding points. This is known as Auspitz sign,\nit is attributed to parakeratosis, intracellular edema of epidermal cells, suprapapillary thinning of stratum Malpighi,\nelongation of dermal papillae and dilatation and tortuosity of papillary capillaries. PSORIASIS:\n\nPink Papules/ Plaques/ Pinpoint bleeding (Auspitz sign)/ Physical injury (Koebner phenomenon)\nSilver Scale/ Sharp margins\nOnycholysis/ Oil Spots\nRete Ridges with Regular elongation\nItching\xa0 Arthritis/ Abscess (Munro)\nStratum corneum with nuclei, neutrophils\nImmunologic disease\nStratum granulosum absent/ Stratum Spinosum thickening. Plaque Psoriasis\nThis is the most common and well-recognized form of psoriasis. 2\nIt is characterized by well-defined raised erythematous papules and plaques with silvery coarse scale.\nThe distribution is typically symmetric, and sites of predilection include\xa0- the extensor surfaces of the extremities, particularly the elbows and knees, sacrum, scalp, nape of the neck, and to a lesser extent trunk, genitalia, face, and ears.\nIndividuals may present with hyperkeratotic scaling disease localized to the scalp only, making it difficult to discriminate from severe seborrheic dermatitis or tinea capitis. This presentation has been called tinea amiantacea, and requires evaluation to distinguish between these 3 entities.\nAdditional features of psoriatic plaques include: - Auspitz sign, - Woronoff ’s ring and - Kobner phenomenon', 'role': 'assistant'}]