Regarding the depth classification of thermal burns, all of the following statements are correct EXCEPT:

Explanation

## Burns Classification by Depth ### Correct Statements (Options 0, 1, 2) **Key Point:** Burns are classified into four degrees based on the depth of tissue involvement. | Degree | Depth | Appearance | Sensation | Healing | |--------|-------|-----------|-----------|----------| | **First** | Epidermis only | Erythema, no blisters | Painful | 3–7 days, no scarring | | **Second** | Partial dermis | Blisters, moist, red | Very painful | 2–3 weeks, minimal scarring | | **Third** | Full thickness (dermis + subcutis) | Charred, leathery, white/brown | Painless | Requires grafting, severe scarring | | **Fourth** | Beyond dermis (muscle, bone) | Charred, eschar | Painless | Requires grafting, amputation possible | **Option 0 (First-degree):** Correct. Involves epidermis only; erythema without blisters is the hallmark. **Option 1 (Second-degree subdivision):** Correct. Superficial partial-thickness burns involve the upper dermis (papillary layer), while deep partial-thickness burns extend into the reticular dermis. **Option 2 (Third-degree):** Correct. Full-thickness burns destroy the entire dermis and extend into subcutaneous tissue; they appear charred, leathery, or white/brown due to coagulation necrosis. ### Incorrect Statement (Option 3) **Option 3 (Fourth-degree):** **This is WRONG.** Fourth-degree burns extend **beyond** the dermis and subcutaneous tissue — they involve muscle, fascia, and bone. They do NOT spare the subcutaneous fat; they destroy it along with deeper structures. The statement falsely claims fourth-degree burns involve "only the epidermis and dermis" with subcutaneous fat remaining intact — this describes third-degree burns, not fourth-degree. **High-Yield:** Fourth-degree burns are the deepest category and carry the highest mortality and morbidity. They require extensive surgical intervention, including possible amputation. **Clinical Pearl:** The distinction between third-degree and fourth-degree burns is critical for prognosis and surgical planning. Third-degree burns may be managed with skin grafting alone; fourth-degree burns often require amputation or extensive reconstructive surgery.