PH 38 (CLINPHARM 2): 1 first clinically visible lesion of acne.
It takes 5 months to develop.

2 plug extends to upper canal and dilates opening;
either oxidized lipid and melanin (black color)
or to the impacted mass of horny cells

Question

1 first clinically visible lesion of acne. 
It takes 5 months to develop.

2 plug extends to upper canal and dilates opening;
either oxidized lipid and melanin (black color) 
or to the impacted mass of horny cells

LEIGHTON DWIGHT OBILLOS · Accepted Answer

1 Closed comedone, or whitehead

2 OPEN comedone or black head

1 first clinically visible lesion of acne. It takes 5 months to develop. 2 plug extends to upper canal and dilates opening; either oxidized lipid and melanin (black color) or to the impacted mass of horny cells