title: Clinical profile of childhood-onset psoriasis and prevalence of HLA-Cw6: a hospital-based study from India.
abstract: BACKGROUND
  Childhood-onset psoriasis (COP), a distinct clinical entity, may be associated with HLA-Cw6 positivity and metabolic and cardiovascular complications. There is some evidence that HLA-Cw6 positivity is associated with more extensive or severe disease and that positivity is lower in Asian patients than in Caucasians. We describe the clinical profile, prevalence of the HLA-Cw6 allele, metabolic syndrome (MetS) and vitamin D deficiency in Indian patients with COP.
  
  
  METHODS
  In this cross-sectional hospital-based study over 15 months (June 2010-August 2011), 108 consecutive patients with disease onset ≤16 years were enrolled. Demographic, clinical and laboratory data were collected. Patients were categorised as children with COP (CCOP; n=69) or adults with COP (ACOP; n=39). Disease severity was assessed using body surface area (BSA) involved and Psoriasis Area and Severity Index (PASI) score.
  
  
  RESULTS
  The most common morphological type was chronic plaque psoriasis; follicular psoriasis was seen only in children. Adults with disease onset in childhood, when compared with CCOP, had later disease onset (11.0±4.0 vs 6.9±3.8 (mean±SD) years; p<0.0001) of greater severity (p=0.021) based on BSA involved. PASI scores were, however, similar in ACOP and CCOP. Body mass index was not associated with disease severity. Of the 83 who underwent HLA-C typing, 46 (55.4%) were positive; positivity was associated with guttate lesions (p=0.031), scalp involvement (p=0.004), greater BSA involvement (p=0.002) and higher PASI scores (p=0.013). Vitamin D deficiency, obesity and MetS were present in 77.4%, 10.7% and 14.5% of patients, respectively.
  
  
  CONCLUSIONS
  Among Indian patients, CCOP have earlier disease onset than ACOP. HLA-Cw6 was associated with guttate psoriasis, scalp involvement and disease severity. Vitamin D deficiency was common.
authors.affiliation: Department of Dermatology, Venereology and Leprosy, Christian Medical College and Hospital, Vellore, Tamil Nadu, India.
authors.forename: Dharshini
authors.initials: D
authors.lastname: Sathishkumar
authors.affiliation: Department of Dermatology, Venereology and Leprosy, Christian Medical College and Hospital, Vellore, Tamil Nadu, India.
authors.forename: Renu
authors.initials: R
authors.lastname: George
authors.affiliation: Department of Transfusion Medicine and Immunohaematology, Christian Medical College and Hospital, Vellore, Tamil Nadu, India.
authors.forename: Dolly
authors.initials: D
authors.lastname: Daniel
authors.affiliation: Department of Medicine, Christian Medical College and Hospital, Vellore, Tamil Nadu, India.
authors.forename: John Victor
authors.initials: JV
authors.lastname: Peter
mesh_terms: D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D015236:HLA-C Antigens / Q000097:blood* / Q000235:genetics; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D011565:Psoriasis / Q000097:blood* / Q000453:epidemiology / Q000235:genetics / Q000276:immunology; D012720:Severity of Illness Index
chemical_list: D015236:HLA-C Antigens; C528994:HLA-C*06 antigen