Treatment should be consistent with any specific injuries that are identified.  Injuries that require treatment are generally only:
Corneal abrasion
Blepharitis
Laryngospasm
Chemical pneumonitis
Shortness of breath
Evaluate and treat any corneal abrasions
Patients with evidence of wheezing and bronchospasm may benefit from albuterol therapy
Most pharyngitis and mucosal irritation will self resolve
Cool water exposure to any irritated or erythematous areas may help reduce cutaneous pain.
Pepper spray
Asthma exacerbation
Magic mouthwash
Caustic keratoconjunctivitis
Tick removal
Blister chemical agents 
Loa loa
Lewisite 