The absence of of pain has even been used to differentiate between partial and full thickness burn injury. Traditional teaching is that full thickness burns are painless due to the cutaneous nerve endings being destroyed. A paper in AJEM suggest it´s not as simple as that.
A retrospective chart review from an American burns center including all burns victims between 2010 and 2013. Burn characteristics described included aetiology, size, location and depth. Pain severity was the primary outcome. Pain was described using a verbal patient score from 0 (none) to 10 (severe).
79% of burns were partial thickness. 2% were first degree burns. 8% were mixed partial and full thickness burns. 4% were unspecified. 7% were isolated full thickness burns.
Mean pain score on ED arrival was 5. Mean pain score in the isolated full thickness burns was 4. Mean pain score in superficial burns was 6.
Only 25% of patients with isolated full thickness burns were pain free on ED arrival.
There was no association between TBSA and pain severity. Increased number of burn wounds were, however, associated with increased pain score.
Most burn victims experience pain. While full thickness burns are somewhat less painfull than partial burns, 75% of patients with full thickness burns have pain. Pain can not be used to differentiate from partial thickness burns in the immediate phase. The authors suggests that this is explained by how even in full thickness injury there is still going to be intact nerve endings.