S20.42 Blister (nonthermal) of back wall of thoraxNon-billable header with 3 child codes.
S20.421 Blister (nonthermal) of right back wall of thoraxS20.422 Blister (nonthermal) of left back wall of thoraxS20.429 Blister (nonthermal) of unspecified back wall of thoraxS20.412S Abrasion of left back wall of thorax, sequelaS20.419 Abrasion of unspecified back wall of thoraxS20.419A Abrasion of unspecified back wall of thorax, initial encounterS20.419D Abrasion of unspecified back wall of thorax, subsequent encounterS20.419S Abrasion of unspecified back wall of thorax, sequelaS20.42 Blister (nonthermal) of back wall of thorax (this code)S20.421 Blister (nonthermal) of right back wall of thoraxS20.421A Blister (nonthermal) of right back wall of thorax, initial encounterS20.421D Blister (nonthermal) of right back wall of thorax, subsequent encounterS20.421S Blister (nonthermal) of right back wall of thorax, sequelaS20.422 Blister (nonthermal) of left back wall of thorax