Primary Lesions:

Macule
Papule
Nodule
Vesicles
Bullar tumors
Wheals

Secondary Lesions:

Erosions
Ulcers
Fissures
Desqumations (excoriations)

Primary lesions of Oral Cavity:
MACULE:
Well circumscribed flat lesions that are noticeable due to the change in color of Skin or Mucosa.
Red- Inflamation
Pigmented- Melanin, Haemosiderin, foreign material.
Ex: Melanotic Macule
PAPULES:
These are solid lesions raised above the Skin or Mucosal surface and are smaller than 1 cm in Diameter.
Ex: Erythema multiformae, lupus erythematous, [...]