Which layer of skin is primarily affected in a second-degree (partial-thickness) burn?

Explanation

## Burn Depth Classification **Key Point:** Second-degree (partial-thickness) burns involve destruction of the epidermis and variable portions of the dermis, with preservation of skin appendages (hair follicles, sweat glands) in the deeper dermis. ### Anatomical Layers Involved | Burn Degree | Depth | Skin Layers | Appearance | Sensation | Healing | |---|---|---|---|---|---| | **1st degree** | Superficial | Epidermis only | Red, dry, no blistering | Painful | 3–7 days, no scarring | | **2nd degree (Partial) | Superficial to deep | Epidermis + dermis | Blistered, moist, red/pink | Very painful | 2–3 weeks, minimal scarring | | **3rd degree (Full)** | Full thickness | Epidermis, dermis, subcutaneous | Charred, leathery, white/brown | Painless | Requires grafting, scarring | | **4th degree** | Beyond skin | Muscle, bone, organs | Carbonized | Painless | Amputation/extensive surgery | **High-Yield:** Second-degree burns are further subdivided: - **Superficial partial-thickness:** Involves upper dermis; blisters form; heals in 1–2 weeks with minimal scarring. - **Deep partial-thickness:** Involves lower dermis; slower healing (3+ weeks); high risk of hypertrophic scarring and contractures. **Clinical Pearl:** The presence of blistering and a moist, weeping surface in second-degree burns indicates viable dermis below the burned epidermis. Pain is preserved because sensory nerve endings in the dermis remain intact. **Mnemonic: "DEPTH"** - **D**egree 1 = Dermis spared (epidermis only) - **E**pidermis + dermis = degree 2 - **P**artial = degrees 1–2 - **T**hickness full = degree 3–4 - **H**ealing varies by depth