Blackheads turn into pustules (become infected) when normally harmless bacteria become aggressive, triggering an immune response in the body. White blood cells arrive at the area to destroy the bacteria, and pus is formed.
Left alone, the immune system can usually treat infected blackheads. This response requires commitment (not to pick at the site) and determination (to allow the skin time to heal). If the infection spreads, consult a skin care specialist.
Benzoyl peroxide, a common ingredient in pimple medications, can shorten recovery time. In concentrations of 2.5 percent to 10 percent, these medications have anti-bacterial properties and dry out pimples.
Salicylic acid corrodes blackhead plugs and allows the trapped sebum to escape naturally. The salicylic acid further kills off the bacteria that contributed to the condition. Salicylic acid products may further irritate the site.
Antibiotics such as tetracycline can help to control the bacteria that contribute to infection formation. These bacteria are normally harmless and consideration should be given to the pros and cons of an extended regimen.
Over-the-counter pore strips bond to the plugs that cause blackheads. When the strips are removed, the plug goes, too, releasing the trapped pus. Keep the opened blemish clean with witch hazel or another antiseptic until it heals.