The presence of HIV/AIDS or other causes of immuno-incompetence (see previous section), a history of having a low-grade lymphoma, and/or the presence of EVB+ plasmablasts in the diseases lesions would support the diagnosis of PBL. Differential diagnosis
Various lymphomas can exhibit the microscopic appearance, including plasmablastic cells, and presentation of PBL. These lymphomas can usually be differentiated from PBL by further examinations of the plasmablasts for various marker proteins and determining other factors that favor the diagnosis of these lymphomas rather than PBL, as indicated in the following descriptions. Anaplastic lymphoma kinase-positive large B-cell lymphoma
Unlike PBL, the plasmablastic cells in anaplastic lymphoma kinase-positive large B-cell lymphoma strongly express the product of the ACVRL1 gene, i.e. activin receptor-like kinase 1 (ALK1) and are not infected with EBV and therefore do not express this viruss EBER or BART RNAs. Human herpesvirus 8-positive diffuse large B-cell lymphoma, not otherwise specified
Unlike PBL, the plasmablastic cells in human herpesvirus 8-positive diffuse large B-cell lymphoma, not otherwise specified express products of herpesvirus 8 (also termed Karposi sarcoma virus) such as LANA-1 protein. Also unlike PBL, these plasmablastic cells do not express CD30, CD138, CD79a, or a clonal IgM antibody and usually are not EBV-infected and therefore usually do not express this viruss EBER or BART RNAs. Primary effusion lymphoma
In contrast to PBL, the plasmablastic cells in primary effusion lymphomas, whether HHV8-positive or HHV8-negative, usually strongly express CD45 and in HHV8 cases express HHV8 proteins such as the LANA-1 protein.
Treatment
Neonatal acne will typically resolve by itself in 2-6 months. In mild cases, cleansing the face daily with gentle soap and water while avoiding use of potential comedogenic soaps, lotions and oils is often enough. Further treatment is not necessary but in severe or persistent cases topical therapy can be initiated. Benzoyl Peroxide
Topical benzoyl peroxide (BPO) may be indicated in persistent or inflammatory cases. BPO is a lipophilic agent that penetrates into sebaceous glands and generates reactive oxygen species that kill P. acnes. It also has comedolytic and anti-inflammatory properties and can prevent development of antimicrobial resistance. Topical Retinoids
Topical retinoids can be used alone or in combination with BPO. Retinoids are derived from vitamin A. They bind to retinoic receptors to normalize the rate of keratinocyte growth and prevent inflammation. Overactive keratinocyte production can lead to comedone formation. Topical Antibiotics
In cases where scarring is a concern, topical antibiotics may be recommended. Topical clindamycin and erythromycin are the most commonly prescribed options for acne. Antibiotics kill P. acnes on skin that could be causing inflammation. With the emergence of resistant P. acnes, experts recommend topical antibiotics to be used in combination with BPO to reduce the risk of development of antimicrobial resistance. The most common side effects of topical antibiotics are stinging, burning and redness at the site of application. Topical antifungals
Some experts suggest the use of topical ketoconazole in newborns with more pustular neonatal acne as there is evidence it shortens duration of lesions.