Corrosion of first degree of thumb (nail)

• birth trauma (P10-P15)
• obstetric trauma (O70-O71)

code to identify any retained foreign body, if applicable (Z18.-)

• Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
• The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

• burns and corrosions of first degree [erythema]
• burns and corrosions of second degree [blisters][epidermal loss]
• burns and corrosions of third degree [deep necrosis of underlying tissue] [full- thickness skin loss]

code from category T31 or T32 to identify extent of body surface involved

(T51-T65) to identify chemical and intent

external cause code to identify place (Y92)

• burns (thermal) from electrical heating appliances
• burns (thermal) from electricity
• burns (thermal) from flame
• burns (thermal) from friction
• burns (thermal) from hot air and hot gases
• burns (thermal) from hot objects
• burns (thermal) from lightning
• burns (thermal) from radiation
• chemical burn [corrosion] (external) (internal)
• scalds

• erythema [dermatitis] ab igne (L59.0)
• radiation-related disorders of the skin and subcutaneous tissue (L55-L59)
• sunburn (L55.-)

The appropriate 7th character is to be added to each code from category T23