Early changes in human epidermis following thermal burn: an electron microscopic study

Area of Science:

• Dermatology
• Cell Biology
• Pathology

Background:

• Thermal burns cause significant skin damage.
• Understanding early cellular responses is crucial for burn treatment.
• Epidermal ultrastructural changes following heat injury require detailed investigation.

Purpose of the Study:

• To investigate the early ultrastructural alterations in human epidermis after thermal burns.
• To characterize the cellular mechanisms leading to blister formation at different temperatures and durations.

Main Methods:

• Human volunteers were subjected to controlled thermal burns (60°C and 95°C).
• Electron microscopy was used to examine epidermal tissue samples.
• Blister formation and keratinocyte morphology were analyzed at the subcellular level.

Main Results:

• A 60°C burn induced blisters via basal cell disintegration and suprabasal cell disruption, showing cytoplasmic vacuoles and mitochondrial changes in keratinocytes.
• A 95°C burn caused complete basal and suprabasal cell breakdown, with karyorrhexis, tonofibril aggregation, and plasma membrane breaks.
• Keratinocytes in blister roofs exhibited peripheral tonofibril aggregation and vacuolization of mitochondria and endoplasmic reticulum.
• Desmosomes and the basement membrane remained unaltered by both burn conditions.

Conclusions:

• Early epidermal damage from thermal burns involves specific ultrastructural changes in keratinocytes.
• Blister formation mechanisms differ based on burn temperature and duration.
• The integrity of desmosomes and the basement membrane suggests initial injury is primarily intracellular and within cell-cell junctions.