Due to delay in growth and identification in these cases, patients may be erroneously classified as "culture-negative" endocarditis. Heart side
Endocarditis can also be classified by the side of the heart affected:

People who intravenously inject opioids such as heroin or methamphetamine may introduce infection which can travel to the right side of the heart, classically affecting the tricuspid valve, and most often caused by S. aureus. Regardless of cause, left-sided endocarditis is more common in people who inject IV drugs and people who do not use substances than right-sided endocarditis. Infection setting
Another form of endocarditis is healthcare-associated endocarditis when the infecting organism is believed to be transmitted in a health care setting like hospital, dialysis unit or a residential nursing home. Nosocomial endocarditis is a form of healthcare associated endocarditis in which the infective organism is acquired during a stay in a hospital and it is usually secondary to presence of intravenous catheters, total parenteral nutrition lines, pacemakers, etc. Valve type
Finally, the distinction between native-valve endocarditis and prosthetic-valve endocarditis is clinically important. Prosthetic valve endocarditis can be early (< 60 days of valvular surgery), intermediate (60 days to 1 year) or late (> 1 year following valvular surgery). Early prosthetic valve endocarditis is usually due to intraoperative contamination or postoperative bacterial contamination which is usually nosocomial in nature. Late prosthetic valve endocarditis is usually due to community-acquired microorganisms.Prosthetic valve endocarditis is commonly caused by Staphylococcus epidermidis as it is capable of growing as a biofilm on plastic surfaces.
Topical antibiotics such as metronidazole and erythromycin have been used for CGPD. Oral antibiotics of the tetracycline class such as minocycline, doxycycline, and tetracycline have been recommended for CGPD. Trimethoprim/sulfamethoxazole has also been used. The use of oral systemic antibiotics is limited by side effects such as nausea, vomiting, and sensitivity of the skin to sunlight. Tetracycline antibiotics are not recommended for children under the age of 8 since tetracyclines are known to deposit in teeth (thereby staining them) and impair bone growth in children.The use of calcineurin inhibitor creams such as tacrolimus or pimecrolimus on the skin is controversial and results have been mixed. Certain studies found the use of topical calcineurin inhibitors led to resolution of CGPD whereas others saw incomplete resolution or prolonged symptoms. Topical azelaic acid has been used successfully to treat CGPD. Immediate discontinuation of topical corticosteroids is recommended since corticosteroids are thought to worsen CGPD. Prognosis
CGPD is known to be a temporary skin disease with a benign course. The skin papules typically resolve after a few months to a few years. After CGPD resolves, the skin may return to normal without scarring or may have small atrophic depressions with collagen loss, milia, or small pit-like scars. Epidemiology
CGPD occurs most often in children of Afro-Caribbean descent  before puberty though reports of this disease occurring in Asian and Caucasian children have also been described. Due to the limited number of reported cases, it remains controversial whether CGPD occurs more often in African children than in children of other races.