ICD-11 classes
01 Certain infectious or parasitic diseases
Mycobacterial diseases
1B20 — Leprosy
1B20.2 — Leprosy reactions
1B20.20 — Type I leprosy reaction

ICD-11 1B20.20 — Type I leprosy reaction

This phenomenon, also named “upgrading reaction,” occurs in borderline leprosy states and is associated with an increase in cell-mediated immunity. It occurs typically within the first 6 months of treatment in previously untreated patients but may be related to stress, intercurrent infections, or pregnancy. Clinical features include inflammatory swelling, erythema and occasionally ulceration of existing lesions, constitutional symptoms and neuritis. If the neuritis is not treated promptly permanent motor nerve damage may ensue.

The diagnosis includes nothing.

The diagnosis excludes nothing.

It has no clarifying diagnoses.

The diagnosis is coded elsewhere:

• Leprosy reactions #15443