Antibiotic exposure is associated with cutaneous adverse events in hairy cell leukemia patients treated with purine analogues

Increased risk of severe cutaneous adverse reactions when cladribine is used together with other medications with a propensity for skin reactions

Cladribine is a purine analog used in first-line treatment of hairy cell leukemia and in relapsed/refractory chronic lymphocytic anemia. Although cladribine is typically associated with mild, self-limited skin reactions, there is increasing evidence that cladribine may increase the risk of severe cutaneous adverse reactions (SCAR) when combined with drugs classically associated with SCAR (e.g. allopurinol) beyond what would be expected for either drug alone, possibly due to cladribine-induced lymphopenia. We analyzed all SCAR cases reported for cladribine in Janssen's Global Safety Database and found that 26/35 (74.3%) reported concomitant drugs known to be associated with SCAR, most commonly sulfamethoxazole/trimethoprim (SMX/TMP) and allopurinol. In addition, a review of the WHO VigiBase showed that several drugs, including penicillins, SMX/TMP, and allopurinol had a statistically significant contribution to cladribine-associated SCAR. These results lend further support that cladribine may increase the propensity of these drugs to cause SCARs.

Skin eruptions in children: Drug hypersensitivity vs viral exanthema

Childhood rashes or exanthemas are common and are usually relatively benign. There are many causes of rash in children, including mainly viruses, and less often bacterial toxins, drugs, allergens and other diseases. Viral exanthema often appears while children are taking a medication in the course of a viral infection; it can mimic drug exanthema and is perceived as a drug allergy in 10% of cases. In the vast majority of cases, the distinction between virus-induced and drug-induced skin eruption during the acute phase is not possible. The drugs most commonly implicated are beta-lactams (BL) and non-steroidal anti-inflammatory drugs (NSAIDs). Viruses, commonly Epstein-Barr virus (EBV), human herpesvirus 6 (HHV6) and cytomegalovirus (CMV), and the bacterium, Mycoplasma pneumoniae, may cause exanthema either from the infection itself (active or latent) or because of interaction with drugs that are taken simultaneously. Determination of the exact diagnosis requires a careful clinical history and thorough physical examination. Haematological and biochemical investigations and histology are not always helpful in differentiating between the two types of exanthema. Serological and polymerase chain reaction (PCR) assays can be helpful, although a concomitant acute infection does not exclude drug hypersensitivity. A drug provocation test (DPT) is although considered the gold standard for the diagnosis and is not preferred by the patients. Skin tests are not well tolerated, and in vitro tests, such as the basophil activation test and lymphocyte transformation, are of low sensitivity and specificity and their relevance is debatable. Based on current evidence, we propose a systematic clinical approach for timely differential diagnosis and management of rashes in children who present a cutaneous eruption while receiving a drug.

The inpatient burden and comorbidities of pyoderma gangrenosum in adults in the United States

Hospital admission is often necessary for management of pyoderma gangrenosum (PG), including wound care and pain control. No large-scale controlled studies examined the burden of hospitalization for PG. The objective of this study is to determine the prevalence, predictors, outcomes, and costs of hospitalization for PG in United States adults. Data were analyzed from the 2002 to 2012 National Inpatient Sample, including a 20% representative sample of United States hospitalizations. The prevalence of hospitalization for PG increased between 2002 and 2012. Primary admission for PG was associated with age 40-59 years, female sex, black race/ethnicity, second-quartile household income, public or no insurance, and multiple chronic conditions. PG admissions were more likely at teaching and medium or large hospitals. Geometric-mean length and cost of hospitalization were higher in inpatients with vs. without a primary diagnosis of PG. The majority of inpatients with PG were classified with minor (64.4%) or moderate (25.7%) likelihood of dying, but moderate (52.5%) and major (28.7%) loss of function. PG was associated with numerous other health disorders. The limitation of this study is the lack of data on PG treatment. This study demonstrated a substantial and increasing inpatient burden of PG in the United States, with considerable disability and mortality risk, multiple comorbid health disorders, and costs.