Keratoconjunctivitis is inflammation ("-itis") of the cornea and conjunctiva. When only the cornea is inflamed, it is called keratitis; when only the conjunctiva is inflamed, it is called conjunctivitis. Causes
There are several potential causes of the inflammation:

Keratoconjunctivitis sicca is used when the inflammation is due to dryness. ("Sicca" means "dryness" in medical contexts.) It occurs with 20% of rheumatoid arthritis patients. The term "vernal keratoconjunctivitis" (VKC) is used to refer to keratoconjunctivitis occurring in spring, and is usually considered to be due to allergens. "Atopic keratoconjunctivitis" is one manifestation of atopy. "Epidemic keratoconjunctivitis" is caused by an adenovirus infection. "Infectious bovine keratoconjunctivitis" (IBK) is a disease affecting cattle caused by the bacteria Moraxella bovis. "Pink eye in sheep and goat" is another infectious keratoconjunctivitis of veterinary concern, mostly caused by Chlamydophila pecorum. "Superior limbic keratoconjunctivitis" is thought to be caused by mechanical trauma. "Keratoconjunctivitis photoelectrica" (arc eye) means inflammation caused by photoelectric UV light. It is a type of ultraviolet keratitis. Such UV exposure can be caused by arc welding without wearing protective eye glass, or by high altitude exposure from sunlight reflected from snow ("snow blindness"). The inflammation will only appear after about 6 to 12 hours. It can be treated by rest, as the inflammation usually heals after 24–48 hours. Proper eye protection should be worn to prevent keratoconjunctivitis photoelectrica. References
External links

eMedicine – on Atopic keratoconjunctivitis
eMedicine – on Epidemic keratoconjunctivitis
Dry skin and atopic dermatitis may co-exist. The patches may become more apparent after sun exposure, when the normal surrounding skin is tanned. The role of ultraviolet radiation, bathing or not bathing, low serum copper and Malassezia yeasts is not clear. Diagnosis
Diagnosis is mainly done by clinical examination. Shining a Woods light over the skin may reveal further lesions not obviously visible otherwise. Differential diagnosis
Pityriasis versicolor and leprosy. Treatment
No treatment is required and the patches in time will settle. The redness, scale and itch if present may be managed with simple emollients and sometimes hydrocortisone, a weak steroid, is also used.As the patches of pityriasis alba do not darken normally in sunlight, effective sun protection helps minimise the discrepancy in colouration against the surrounding normal skin. Cosmetic camouflage may be required. Tacrolimus has been reported as speeding resolution.In exceptionally severe cases PUVA therapy may be considered. Prognosis
The patches of pityriasis alba may last from 1 month to about one year, but commonly on the face last a year. However it is possible that the white patches may last for more than 1 year on the face. Epidemiology
It occurs in mainly children and adolescents of all races, particularly people with dark skin. The worldwide prevalence is 5% in children, with boys and girls affected equally. adults can also have this disease.Up to a third of US school children may at some stage have this condition. Single-point prevalence studies from India have shown variable rates from 8.4%
to 31%.