<prompt> Which of the following is are the side effect s of using argon laser ?HypopigmentationCrustingKeloid formationAll the above  <response>: Ans. is d i.e., All the above Argon Laser Wavelength 488 - 514 nm Penetration depth of 1 mm, which can be increased by cooling Side effects: crusting and possible blistering of skin, irreversible hypopigmentation, transient hyperpigmentation, punctate atrophic or hyperophic scars, keloid formation. 