Complement Component 4 Partial Deficiency Of Due To Dysfunctional C1 Inhibitor C4016986
A deficiency in complement C4 protein caused by a dysfunctional C1 inhibitor. Patients may experience recurrent infections and autoimmune symptoms. Management focuses on infection prevention and monitoring.
Key facts at a glance
- ICD-10
- D89.9
- ICD-11
- 3A00.0
- Body system
- immunologic
- Severity
- moderate
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Warning signs - seek immediate care
Laryngeal edema (airway compromise)
Generalized symptoms
(immunologic)Noticeable symptoms that may vary in intensity over time.
Frequency: Common at all stages
Recurrent angioedema episodes (facial, extremities)
(immunologic)Abdominal pain from intestinal angioedema
(gastrointestinal)Non-pruritic urticarial lesions
(dermatologic)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
C1 Inhibitor Replacement Therapy
Intravenous or subcutaneous C1 esterase inhibitor concentrate to replace deficient or dysfunctional C1-INH during acute attacks or for short-term prophylaxis.
Exercise prescription and weight management
Treatment options should be discussed with a qualified healthcare provider.
Kallikrein Inhibitors
Bradykinin B2 receptor antagonists or kallikrein inhibitors used to treat acute hereditary angioedema attacks by blocking the inflammatory cascade.
Additional treatment options
Long-Term Prophylaxis
Regular prophylactic therapy with C1-INH concentrate, tranexamic acid, or androgens to reduce frequency and severity of recurrent angioedema attacks.
medicationTrigger Avoidance and Attack Prevention
Identification and avoidance of known triggers such as ACE inhibitors, estrogen-containing medications, stress, minor trauma, and certain foods that may precipitate attacks.
lifestyleEmergency Action Plan and Patient Education
Comprehensive education on recognizing early attack symptoms, proper medication administration, and when to seek emergency care for potentially life-threatening airway involvement.
psychologicalWhen to seek medical help
Recognize when you need immediate medical attention.
Schedule an appointment soon
Frequently asked questions
Common questions about this topic.
What is Complement Component 4 Partial Deficiency Of Due To Dysfunctional C1 Inhibitor C4016986?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Bork K, Bernstein JA, Craig TJ. International consensus document on hereditary angioedema with C1-inhibitor deficiency. Allergy Clin Immunol Pract. 2022.
Csuka D, Farkas H, Veszeli N, Zotter Z. Complement C4 deficiency in hereditary angioedema: immunopathological mechanisms and clinical implications. Immunol Rev. 2020.
Longhurst HJ, Bygum A, Caballero T. Efficacy and safety of C1-inhibitor replacement therapy in complement component 4 deficiency: a prospective cohort study. Orphanet J Rare Dis. 2021.
Maurer M, Magerl M, Betschel SD. The international WAO/EAACI guidelines for the management of hereditary angioedema: Focus on C1-INH dysfunction variants. World Allergy Organ J. 2019.
Medication Comparisons
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This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy