Tehran University Medical Journal

Background: Rash is a common complaint in children that has many causes and the various differential diagnoses. Therefore, urgent and appropriate clinical diagnosis is necessary to provide immediate medical intervention. Therefore, the purpose of this study was to investigate the causes of skin rash in children hospitalized due to rash.
Methods: This descriptive-analytic study was performed on all patients admitted for skin rashes in Hazrat Masoumeh Hospital in Qom, Iran from 2010 to 2015. In this study, the data of 317 patients who were admitted to the early diagnosis of rash were collected from patients' files and recorded in the checklist.
Results: According to our study, the most common causes of skin rashes in children were viruses with a share of 40.69% (129 cases), allergic causes being as prevalent as 21.77% (69 cases) and drug induced rashes that accounted for 20.50% (65 cases). Based on the site and type of rashes, the most common type of rashes were maculopapular rashes with 42% and hives with 31.9% prevalence, and the most common site of involvement was diffuse involvement that would account for 84% of the cases. In terms of drug use history, 35.6% had a history of antibiotic use prior to admission, and 14.5% had an antiepileptic drug use history. There was a significant relationship between the cause of rashes and the season of presentation (P< 0.05) as well as the age of presentation (P< 0.05).
Conclusion: This study showed that there is a significant relationship between the season and age of occurrence, but the use of these factors as a benchmark for the diagnosis of rash requires more studies. Paying attention to the causes of rash in children, knowing about these factors, and continuous evaluation of these patients can help in advancing a proper management of the problem of patients. The most frequent factors were viruses and then allergic and pharmaceutical agents, and the most common type was maculopapular.

Background: Methotrexate is an anti-metabolite drug and one of the folic acid analog that it can play an important and functional role in the treatment of many malignancies and inflammatory diseases. However, the development of petechiae (maculopapular rash) is a very rare complication.
Case Presentation: The patient was a 77 years old woman, Aryan race, who was known a case of severe and progressive rheumatoid arthritis. She previously was treated by multiple drugs such as salicylates, gold, corticosteroids, because of unresponsiveness to these drugs, physician prescribed methotrexate once a day, but patient misunderstands and use three times per day for days. Patient with this history referred to a poisoning emergency. In a physical exam, she had oral and throat erythema and swelling of mucosa. In the funduscopy of eyes, bottom of the eyes was normal and conjunctival eyes were prurient she had multiple petechiae at the upper part of chest and base of neck and shoulders and arms with no swelling around petechiae. The lesion had no itching. She had no other sign besides laboratory analysis showed a high level of creatinine, leukopenia, decreased the level of platelets, patient with high suspicious of methotrexate poisoning underwent to granulocyte-macrophage colony-stimulating factor (GM-CSF) and folic acid treatment. After treatment all of her signs recovered and laboratory tests became normal.
Conclusion: At the time of taking methotrexate by the patient, even with appointment of a specialist physician, with any skin signs such as maculopapular rash without itching, we should consider poisoning with methotrexate, and think appropriately about it. This suggests that methotrexate can cause side effects even at low doses.