| Trauma during the early stages of evolution may induce the isomorphic phenomenon to produce a linear distribution of papules. |
| Mild acne is characterized by the presence of few to several papules and pustules, but no nodules. |
| Erythematous papules and pustules characterize inflammatory acne, but comedones may also be present. |
| The most common presenting lesions are papules, vesicles, pustules, and nodules. |
| It is characterized by pruritic, of ten excoriated papules and nodules on the extensor surfaces of the legs and upper arms. |
| The lesions develop into 1-5 mm yellow-grey papules or pustules, with surrounding erythema, confined to the follicular ostia. |
