title: Allergic conjunctivitis in Jos-Nigeria.
abstract: BACKGROUND
  Allergic conjunctivitis (AC) may follow seasonal or perennial pattern. There are climatic and racial risk factors involved in some types of AC. It is more prevalent in warm climatic conditions and among Afro-Caribbeans, Arabs and Asians and less among the White populations. Clinical presentations also seem to follow climatic and genetic predisposition. The purpose of this study is to determine the prevalence of AC and its clinical presentations in a hospital setting in this region in people of all ages.
  
  
  METHODS
  This is a hospital-based retrospective study of new patients seen at Adoose Specialist Hospital, Jos the capital city of Plateau State in North Central Nigeria with clinical diagnosis of AC from 2000 to 2009.
  
  
  RESULTS
  There were 972 subjects, 474 (48.8%) males and 498 (51.2%) females with M:F ratio of 1:1.05. The most common symptom was itching followed by redness, pains, watery/mucoid discharge, sticky eyes, puffy eyes and photophobia. The presence of papillae in the upper tarsal or lower conjunctiva, a discrete or confluent gelatinous hypertrophy of the limbal conjunctiva (Trantas dots), hyperpigmentation, hyperemia/chemosis of the conjunctiva were the common signs. AC was more prevalent in those aged 1-16 years 38.4% decreasing to 4.9% in the age group above 50 years. The presentation followed perennial pattern, with a peak around July. The most prevalent ocular comorbid condition was refractive error (distant RE and presbyopia) in 15.4%, followed by pterygium/pinguecula 3.6%, bacterial conjunctivitis in 2.2%, glaucoma 2.1% and eyelid disorders 1.7%. Cataract was present in 1.3%, and keratopathy 1.1%. Other conditions such as episcleritis, dry eye, vitamin A deficiency and posterior segment disease were also present in decreasing order. Systemic association were few with generalised body atopy in 0.3%.
  
  
  CONCLUSIONS
  The prevalence of AC was 32% and is similar to what pertains in some of the African hospital studies, but differs in presentation from the Caucasians.
authors.affiliation: Department of Ophthalmology, Benue State University Teaching Hospital, Makurdi, Benue, Nigeria.
authors.forename: Keziah N
authors.initials: KN
authors.lastname: Malu
keywords: African continent; Allergic conjunctivitis; perennial and seasonal variations