Page 11 of 12

DR13.1-2 | Vesiculobullous Lesions — Assignment

CLINICAL SCENARIO

You will work through a constructed clinical vignette of a patient with a suspected autoimmune vesiculobullous disorder and produce a structured written reasoning report. This assignment develops the diagnostic reasoning and primary management skills required by DR13.1 and DR13.2.

Instructions

Read the clinical vignette below carefully. Then complete each section of the scaffolded report in your own words. You must justify every clinical decision with reference to the pathophysiology you have studied. Do NOT copy definitions from textbooks — demonstrate that you can reason from a clinical observation to a mechanistic explanation.

Clinical Vignette

Mrs. K, a 47-year-old primary school teacher, presents to a district hospital with a 5-week history of painful sores in the mouth that have prevented her from eating solid food. Over the past 10 days, multiple fragile blisters have appeared on her chest, back, and upper arms. The blisters rupture spontaneously or with minimal friction, leaving raw, weeping erosions. She denies any recent drug use or fever. On examination, temperature is 37.4 °C; pulse 96/min; blood pressure 108/72 mmHg; weight 52 kg (down from 58 kg six weeks ago). The oral mucosa shows 6–8 ragged erosions on the buccal surfaces and soft palate. The trunk has approximately 20 erosions (2–6 cm) and 4 intact blisters. A firm lateral stroke with the index finger on normal-appearing skin adjacent to an erosion causes the superficial epidermis to slide off over a 2-cm area.

Length: Total 950–1100 words across all five sections. Stay within the per-section guidance. Concision is valued over length.

What to Submit

Identify the bedside sign elicited in the vignette. Name it, describe the technique used, interpret the result (positive or negative), and explain in 3–4 sentences the tissue-level mechanism that makes this sign positive in this patient. State which disease(s) this result supports and which it argues against.

State your most probable diagnosis. Then list TWO differential diagnoses that must be considered and briefly explain (2–3 sentences each) why the clinical findings support or exclude each alternative. Structure your answer as: Probable diagnosis → pathophysiological justification → Differential 1 → supporting/excluding features → Differential 2 → supporting/excluding features.

Describe the TWO investigations that are required to confirm your diagnosis histopathologically and immunologically. For each investigation: (a) state exactly what specimen is taken and from which site, (b) describe the expected finding, and (c) explain what the finding means at the molecular level.

Outline your complete primary management plan for Mrs. K. Organise your answer under: (A) immediate supportive care — address why IV fluids and nutritional support are needed, what wound care is appropriate, which analgesics are appropriate, and what nursing precautions apply to the fragile skin; (B) pharmacological management you would initiate before specialist review; (C) referral — to whom, with what urgency, and what information you would communicate in the referral letter. Justify each decision.

List FOUR specific clinical observations or laboratory parameters you would monitor in Mrs. K over the next 48 hours while awaiting transfer. For each, state: the parameter, the threshold that would prompt an immediate escalation action, and the action you would take. Present this as a structured table.

Grading Rubric — Vesiculobullous Lesions Assignment Rubric (50 points total)

Criterion	Points	Full-marks descriptor
Section 1 — Bedside Sign: Correct identification, technique description, positive/negative interpretation, mechanistic explanation, and differential implications	10 pts	Correctly identifies Nikolsky sign; describes tangential pressure on perilesional normal skin; calls result positive; explains suprabasal acantholysis from anti-Dsg3 IgG loss of desmosomal adhesion in mechanistic language; correctly states PV supported, BP excluded (Nikolsky negative in BP).
Section 2 — Diagnosis and Differential: Correct probable diagnosis with pathophysiological justification; two appropriate differentials with supporting/excluding reasoning	10 pts	States PV as probable diagnosis with correct pathophysiological basis (anti-Dsg3 IgG, suprabasal split, oral-first onset). Chooses two appropriate differentials (e.g., bullous pemphigoid, SJS/TEN, or mucous membrane pemphigoid) and correctly argues supporting/excluding features for each.
Section 3 — Investigations: Two correct investigations (H&E biopsy + DIF perilesional), specimen details, expected findings, and molecular interpretation	10 pts	Names H&E biopsy (from blister edge) and DIF of PERILESIONAL skin (2 cm from lesion); correctly states H&E shows suprabasal acantholysis with tombstone sign; DIF shows intercellular IgG/C3 chicken-wire pattern; explains IgG binding desmoglein on keratinocyte surfaces.
Section 4 — Primary Management: Supportive care (IV fluids, wound care, nursing precautions), pharmacological plan, referral with urgency and content	12 pts	IV fluids justified by transepidermal fluid/protein loss; non-adherent dressings specified (no adhesive tape — iatrogenic Nikolsky risk mentioned); adequate analgesia; nutritional support noted; systemic corticosteroids as definitive therapy discussed with steroid monitoring plan; referral to dermatologist with urgency and appropriate information in referral letter.
Section 5 — Monitoring and Red Flags: Four parameters with thresholds and escalation actions in a structured table	8 pts	Four clinically relevant parameters in tabular format (e.g., temperature >38.5°C → blood culture + antibiotics; serum albumin <2.5 g/dL → IV albumin/nutritionist; urine output <0.5 mL/kg/hr → IV fluid bolus; BSA of denuded skin increasing → escalate steroid dose + urgent transfer); thresholds specific and actions actionable.

PEER REVIEW

You will review one peer's assignment anonymously. Read their entire response first before scoring any section. For each rubric criterion: (1) assign a score, (2) write 2–3 sentences of specific, constructive feedback — quote the student's text if helpful. Do not simply say 'good' or 'needs improvement'; explain WHY. Pay particular attention to whether your peer has correctly distinguished pemphigus vulgaris from bullous pemphigoid — reversing clinical features (e.g., calling Nikolsky negative in PV) is a high-stakes error in clinical practice.