Psoriasis MCQs

Autoimmune destruction of pancreatic beta cells: This describes Type 1 diabetes, not psoriasis. Hyperproliferation of keratinocytes: Psoriasis is characterized by the rapid turnover and proliferation of skin cells (keratinocytes), leading to thickened skin and scaling. Immune-mediated destruction of the thyroid gland: This is seen in Hashimoto’s thyroiditis, not psoriasis. Defective T cell maturation in the thymus: This is related to autoimmune lymphoproliferative syndrome, not psoriasis. Key Takeaway: Psoriasis is primarily due to the hyperproliferation of keratinocytes. Tags: Good to know Tag Line: Moderate Reference: Shastri, A., & Bhatt, S. (2023). Essential Microbiology . Chapter 17: Autoimmunity, pp. 203-207

Chloroquine is contraindicated in patients with psoriasis or porphyria, in whom it may precipitate acute attacks of these diseases. It should generally not be used in those with retinal or visual field abnormalities or myopathy. Chloroquine should be used with caution in patients with a history of liver disease or neurologic or hematologic disorders. The antidiarrheal agent kaolin and calcium-and magnesium-containing antacids interfere with the absorption of chloroquine and should not be co-administered with the drug. Chloroquine is considered safe in pregnancy and for young children. Reference: LANG' Basic & clinical pharmacology by Bertram G. Katzung, Susen B. Masters and Anthony J. Trevor 12 th edition. Chapter 52- Antiprotozoal Agents by Dr. Philip J. Rosenthal. Page no. 920

Explanation: The stratum basale expresses keratin 5 (K5) and keratin 14 (K14). These keratins provide structural support to the basal keratinocytes, which are mitotically active and attached to the basement membrane. Mutations in K5 or K14 lead to epidermolysis bullosa simplex. Keratin expression by epidermal layer: Stratum basale: K5/K14 Stratum spinosum & granulosum: K1/K10 Non-keratinizing epithelia (eg. esophagus): K4/K13 Hyperproliferative states (psoriasis, wound healing): K6/K16 Clinical relevance: Keratin profiling helps diagnose blistering disorders

Pustule of Psoriasis (Clusters of neutrophils) Sponge-like array in the stratum spinosum - Spongiform pustule of Kogoj's In the stratum corneum - Microabscess of Munro Other features - parakeratosis, hypogranulosis, regular elongation of rete ridges, supra-papillary thinning, dilated tortuous dermal capillaries Reference: Rooks textbook of dermatology, 9 th edition, chapter 35, page 7

Explanation: Darier's disease (keratosis follicularis) shows dyskeratosis with hallmark histological features: Corps ronds Grains These represent prematurely keratinized cells within the epidermis. It is a genetic disorder caused by mutations in the ATP2A2 gene affecting calcium regulation in keratinocytes. Dyskeratosis: Abnormal keratinization occurring below the stratum granulosum Seen in conditions where integrity of epidermal adhesion or keratinization is altered Conditions associated with dyskeratosis: Darier's disease (most classic) Warty dyskeratoma Grover's disease (transient acantholytic dermatosis) Pemphigus vulgaris: Shows acantholysis (Option B) Psoriasis: Shows hyperproliferation with parakeratosis (Option C) Lichen planus: Shows hyper granulosis and saw-tooth rete ridges (Option D)

Psoriasis Lesions Show positive auspitz sign - pin point bleeding on scratching with a glass slide (Grattage test ) Auspitz sign: Not diagnostic of psoriasis but when positive, helps in pointing to it. Skin biopsy is investigation of choice Reference: Rooks textbook of dermatology, 9 th edition, chapter 35, page 8

Psoriasis and metabolic syndrome> Vitiligo and metabolic syndrome

Arthritis + Conjunctivitis + NGU Iridocyclitis & conjunctivitis Mucocutaneous lesions: Rupioid psoriasis, /Keratoderma blennorrhagicum (crusted, exudative plaques on palms and soles) and Circinate balanitis Reference: Rook's dermatology, 9 th Edition, Chapter 154, Page 2