orris logo New Chat Yesterday Generate Title User Solve I'll analyze this medical exam paper and solve all questions. Let me read the skill file and search the medical library simultaneously. Searched 2 sources Based on the image provided, here is the complete text extracted from the exam paper: FIRST INTERNAL ASSESSMENT 3rd PROFESSIONAL MBBS Time: 1 hour Marks: 30 Q 1. A 24-year-old male presents with itching over the groin and inner thighs for 3 months. Examination reveals multiple annular erythematous plaques with active scaly margins and central clearing. a) What is the most likely diagnosis? (1 mark) b) Mention two common causative organisms. (1 mark) c) Describe two bedside/laboratory investigations that help confirm the diagnosis. (2 marks) d) Outline the treatment of this patient, mentioning one topical and one systemic antifungal agent. (2 marks) Q 2. A 10-year-old child presents with recurrent itchy lesions involving the flexures of elbows and knees since early childhood. There is a personal history of allergic rhinitis. a) What is the most likely diagnosis? (2 mark) b) Mention two factors involved in its etiopathogenesis. (2 marks) c) Outline the management mentioning one topical and two systemic agents for this condition. (2 marks) Q 3. A 35-year-old man presents with a hypopigmented patch over the forearm associated with loss of sensation. Examination reveals thickening of the ulnar nerve. a) What is the most likely diagnosis? (1 mark) b) Mention two cardinal signs of this condition. (1 mark) c) Mention two investigations (bedside/laboratory) that can help in confirmation of diagnosis. (2 marks) d) Write the WHO-recommended regimen for this patient. (2 marks) Q 4. A 28-year-old sexually active man presents with a single painless ulcer on the genitalia for 10 days. Examination reveals a clean-based indurated ulcer with non-tender inguinal lymphadenopathy. a) What is the most likely diagnosis and stage of disease? **(2 marks)**Now I have the full question text. Let me search the medical library for all four topics simultaneously. Searched 4 sources Good. Let me get more detail from the dermatology textbook for tinea cruris and search the other topics with better queries. Searched 4 sources Let me get more detail from the best sources for atopic dermatitis, leprosy, and syphilis. Searched 3 sources I now have strong textbook-backed data for all four questions. Let me compile comprehensive answers. FIRST INTERNAL ASSESSMENT - 3rd Professional MBBS: Complete Answers Q1. 24-year-old male, itching over groin and inner thighs for 3 months. Multiple annular erythematous plaques with active scaly margins and central clearing. a) Most likely diagnosis (1 mark) Tinea cruris (Dermatophytosis of the groin / "Jock itch") The classic presentation - annular erythematous plaques with a raised, scaly advancing border and central clearing in the inguinal region of a young male - is pathognomonic of tinea cruris. b) Two common causative organisms (1 mark) Trichophyton rubrum (most common overall) Epidermophyton floccosum (T. mentagrophytes is a third agent - Dermatology 5e confirms: "The three most common causative agents are Epidermophyton floccosum, T. rubrum, and T. mentagrophytes") c) Two bedside/laboratory investigations to confirm diagnosis (2 marks) KOH mount (Potassium Hydroxide preparation) - bedside test: skin scrapings from the active scaly margin are dissolved in 10-20% KOH and examined microscopically for fungal hyphae (septate branching hyphae = dermatophyte infection) Fungal culture (Sabouraud Dextrose Agar) - definitive laboratory test identifying the specific causative dermatophyte species d) Treatment - one topical + one systemic antifungal (2 marks) Topical: Clotrimazole 1% cream applied twice daily for 2-4 weeks (alternatively: terbinafine cream, miconazole, or ketoconazole cream) Systemic: Oral terbinafine 250 mg once daily for 2 weeks (alternatively: itraconazole 200 mg/day for 1 week, or fluconazole 150 mg weekly for 2-4 weeks) Q2. 10-year-old child, recurrent itchy lesions in flexures of elbows and knees since early childhood. Personal history of allergic rhinitis. a) Most likely diagnosis (2 marks) Atopic Dermatitis (Atopic Eczema) The triad of: (1) flexural itch, (2) onset since early childhood, and (3) personal atopic history (allergic rhinitis) fulfills major Hanifin-Rajka diagnostic criteria for atopic dermatitis. b) Two factors in etiopathogenesis (2 marks) Immunological/genetic dysregulation - Th2 skewed immune response with elevated IgE: There is a genetic predisposition causing a polarized Th2 lymphocyte response, resulting in excess IL-4, IL-5, IL-13, and markedly raised serum IgE levels, leading to sensitization, mast cell activation, and eosinophilia. This drives the allergic inflammation. Epidermal barrier dysfunction (filaggrin gene mutation): Loss-of-function mutations in the FLG gene encoding filaggrin reduce the skin's barrier integrity, causing increased trans-epidermal water loss (TEWL), skin dryness, and enhanced allergen penetration - which in turn triggers further immune activation. c) Management - one topical + two systemic agents (2 marks) Topical: Topical corticosteroids (e.g., hydrocortisone 1% for mild; betamethasone valerate for moderate-severe) applied to affected areas to reduce inflammation. Alternatively, topical calcineurin inhibitors (tacrolimus/pimecrolimus) for sensitive areas. Systemic agent 1: Oral antihistamines (e.g., cetirizine or hydroxyzine) - to control pruritus, especially at night Systemic agent 2: Oral corticosteroids (e.g., prednisolone) for acute severe flares; or cyclosporine (immunosuppressant) for chronic severe/refractory cases Q3. 35-year-old man, hypopigmented patch over forearm + loss of sensation + thickening of ulnar nerve a) Most likely diagnosis (1 mark) Leprosy (Hansen's Disease - caused by Mycobacterium leprae) The combination of a hypopigmented anaesthetic patch with peripheral nerve thickening (ulnar nerve) is the hallmark presentation of leprosy. b) Two cardinal signs of leprosy (1 mark) The WHO defines three cardinal signs; any two from: Hypopigmented (or erythematous) skin lesion(s) with definite loss of sensation Thickened peripheral nerve (e.g., ulnar, radial cutaneous, common peroneal, posterior tibial, facial, great auricular nerve) Demonstration of acid-fast bacilli (AFB) in slit-skin smear (sometimes counted as a third cardinal sign) c) Two investigations (bedside/laboratory) for confirmation (2 marks) Slit-Skin Smear (SSS) - bedside: a small incision is made at the lesion site/ear lobe, tissue fluid smear stained with Ziehl-Neelsen stain to detect AFB (Mycobacterium leprae). Gives the Bacteriological Index (BI). Skin biopsy - histopathological examination showing granuloma type (tuberculoid granuloma in TT/BT; foamy macrophages/Virchow cells laden with AFB in LL leprosy). Alternatively: Lepromin (Mitsuda) test - intradermal injection to assess cell-mediated immunity (positive in tuberculoid, negative in lepromatous). d) WHO-recommended treatment regimen (2 marks) Based on classification: This patient has a single hypopigmented patch with nerve involvement → classify clinically as Paucibacillary (PB) leprosy (1-5 skin lesions, SSS negative): WHO MDT regimen for Paucibacillary leprosy (6 months): Drug Dose Frequency Rifampicin 600 mg Supervised Monthly Dapsone 100 mg Self-administered Daily Duration: 6 months (If smear-positive / multibacillary: Rifampicin 600 mg monthly + Clofazimine 300 mg monthly supervised + Clofazimine 50 mg daily + Dapsone 100 mg daily for 12 months) Q4. 28-year-old sexually active man, single painless ulcer on genitalia for 10 days. Clean-based indurated ulcer + non-tender inguinal lymphadenopathy. a) Most likely diagnosis and stage of disease (2 marks) Diagnosis: Primary Syphilis (caused by Treponema pallidum) Stage: Primary stage The classic features pointing to this diagnosis: Single painless indurated ulcer = syphilitic chancre (the "clean-based indurated ulcer" with rolled edges) Non-tender inguinal lymphadenopathy = regional adenopathy (firm, rubbery, non-tender nodes) Sexually active, ulcer present for 10 days (incubation 10-90 days, average 3 weeks) Dermatology 5e confirms: "The chancre usually presents as a single, indolent, round or oval, indurated ulcer that is associated with regional adenopathy... Untreated, chancres heal within a few weeks." Note on Q4: The image is partially cut off - only part (a) is visible. If there are further parts (b, c, d), they likely ask about: (b) investigations - darkfield microscopy / VDRL + TPHA; (c) treatment - benzathine penicillin G 2.4 million units IM single dose; (d) contacts/partner tracing. Quick Reference Summary Q Condition Key Organism/Cause Key Test Key Treatment 1 Tinea Cruris T. rubrum, E. floccosum KOH mount Topical clotrimazole + oral terbinafine 2 Atopic Dermatitis FLG mutation + Th2/IgE dysregulation Clinical (Hanifin-Rajka) Topical steroids + antihistamines + systemic steroids/cyclosporine 3 Leprosy M. leprae Slit-skin smear + biopsy WHO MDT (Rifampicin + Dapsone × 6 months PB) 4 Primary Syphilis T. pallidum Darkfield microscopy / serology Benzathine penicillin G 2.4 MU IM Sources: Dermatology 2-Volume Set 5e (Elsevier); Andrews' Diseases of the Skin; Tintinalli's Emergency Medicine; Sherris & Ryan's Medical Microbiology 8e Follow-up suggestions 1 Create a summary document with differential diagnosis tables for genital ulcers and skin lesions 2 Generate a quick reference PDF on dermatological investigations (KOH, cultures, histology) 3 Search for recent WHO guidelines on leprosy and syphilis management 4 Make a study guide comparing the four conditions covered in this exam Ask Orris Orris – AI Clinical Decision Support