Thanks for posting your query at DoctorSpring.com
I can understand your concern.
These do seem like acne. However they are called acneiform eruption which happen after drug intake. Humira is not known to cause acneiform eruptions in literature, however it could still occur.
Alternatively they could be just folliculitis which occur due to bacterial infection of the skin
(of the hair follicles)
I would recommend application of mupirocin cream on the lesions for a week, twice daily and see if it helps.
Humira can result in dryness and cracking of the skin. I would recommend application of a moisturizing cream containing urea.
In the cracked skin, you could put the mupirocin cream twice daily which will help in effective healing of the fissures.
Please let me know if you have any queries.