Which of the following histological features is characteristic of a deep partial-thickness (2nd degree deep) burn?

## Deep Partial-Thickness (2nd Degree Deep) Burns **Key Point:** Deep partial-thickness burns destroy the epidermis and extend into the deep dermis, destroying most dermal appendages (hair follicles, sebaceous glands, sweat glands) but leaving subcutaneous tissue intact. ### Histological Depth Classification | Burn Depth | Epidermis | Dermis | Appendages | Appearance | |---|---|---|---|---| | Superficial (1st degree) | Destroyed | Intact | Preserved | Red, painful, no blistering | | Superficial partial (2nd shallow) | Destroyed | Superficial destroyed | Preserved | Blistered, pink, painful | | Deep partial (2nd deep) | Destroyed | Deep destroyed | Lost | White/mottled, less painful | | Full thickness (3rd degree) | Destroyed | Completely destroyed | Lost | Charred, painless, leathery | **High-Yield:** Deep partial-thickness burns destroy the dermal appendages, which are the source of re-epithelialization. This is why they require grafting for optimal healing and have higher scarring risk compared to superficial partial-thickness burns. **Clinical Pearl:** The presence or absence of dermal appendages is the critical histological distinction between superficial and deep partial-thickness burns — both destroy the epidermis, but deep burns eliminate the regenerative potential of skin adnexa. ### Why Healing Differs Superficial partial-thickness burns can re-epithelialize from preserved hair follicles and sweat gland ducts (epithelial remnants). Deep partial-thickness burns lack these sources, necessitating surgical grafting for timely closure and reducing contracture risk.