| Type |
Age of onset |
Incidence (%) |
Clinical manifestations |
Prognosis |
| I (classical adult)
|
Adult |
55 |
Confluent red-orange plaques with islands of sparing in generalized distribution. Follicular keratotic papules. Waxy palmoplantar keratoderma. |
Spontaneous resolution in 80% of cases with 3 years |
| II (atypical juvenile) |
Adult |
5 |
Ichthyosiform scale in generalized distribution with areas of dermatitis and alopecia. Palmoplanter keratoderma with lamellated scaling. |
Chronic course |
| III (classical juvenile) |
5-10 years |
10 |
Similar to type I. |
Most resolve within 1 year |
| IV (circumscribed juvenile) |
3-10 years |
25 |
Follicular hyperkeratosis, mainly of the knees and elbows. Only type to be localized. |
Unclear |
| V (atypical juvenile) |
0-4 years |
5 |
Follicular hyperkeratosis in generalized distribution. |
Chronic course |
| VI (HIV-associated) |
Variable |
Unclear |
Similar to type I. Associated with acne conglobata and hidradenitis suppuritiva. |
Variable |
