Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors
Search in posts
Search in pages
Filter by Categories
15th National Conference of the IAOMFP, Chennai, 2006
Abstracts from current literature
Acne in India: Guidelines for management - IAA Consensus Document
Art & Psychiatry
Association Activities
Association Notes
Award Article
Book Review
Brief Report
Case Analysis
Case Letter
Case Letters
Case Notes
Case Report
Case Reports
Clinical and Laboratory Investigations
Clinical Article
Clinical Studies
Clinical Study
Conference Oration
Conference Summary
Continuing Medical Education
Cosmetic Dermatology
Current Best Evidence
Current Issue
Current View
Derma Quest
Dermato Surgery
Dermatosurgery Specials
Dispensing Pearl
Do you know?
Drug Dialogues
Editor Speaks
Editorial Remarks
Editorial Report
Editorial Report - 2007
Editorial report for 2004-2005
Fourth All India Conference Programme
From Our Book Shelf
From the Desk of Chief Editor
Get Set for Net
Get set for the net
Guest Article
Guest Editorial
How I Manage?
IADVL Announcement
IADVL Announcements
IJDVL Awards
IJDVL Awards 2018
IJDVL Awards 2019
IJDVL Awards 2020
IJDVL International Awards 2018
Images in Clinical Practice
In Memorium
Inaugural Address
Knowledge From World Contemporaries
Leprosy Section
Letter in Response to Previous Publication
Letter to Editor
Letter to the Editor
Letter to the Editor - Case Letter
Letter to the Editor - Letter in Response to Published Article
Letter to the Editor - Observation Letter
Letter to the Editor - Study Letter
Letter to the Editor - Therapy Letter
Letter to the Editor: Articles in Response to Previously Published Articles
Letters in Response to Previous Publication
Letters to the Editor
Letters to the Editor - Letter in Response to Previously Published Articles
Letters to the Editor: Case Letters
Letters to the Editor: Letters in Response to Previously Published Articles
Medicolegal Window
Miscellaneous Letter
Net Case
Net case report
Net Image
Net Letter
Net Quiz
Net Study
New Preparations
News & Views
Observation Letter
Observation Letters
Original Article
Original Contributions
Pattern of Skin Diseases
Pediatric Dermatology
Pediatric Rounds
Presedential Address
Presidential Address
Presidents Remarks
Report of chief editor
Report of Hon : Treasurer IADVL
Report of Hon. General Secretary IADVL
Research Methdology
Research Methodology
Resident page
Resident's Page
Resident’s Page
Residents' Corner
Residents' Corner
Residents' Page
Review Article
Review Articles
Reviewers 2022
Revision Corner
Self Assessment Programme
Seminar: Chronic Arsenicosis in India
Seminar: HIV Infection
Short Communication
Short Communications
Short Report
Special Article
Specialty Interface
Study Letter
Study Letters
Symposium - Contact Dermatitis
Symposium - Lasers
Symposium - Pediatric Dermatoses
Symposium - Psoriasis
Symposium - Vesicobullous Disorders
Symposium Aesthetic Surgery
Symposium Dermatopathology
Symposium-Hair Disorders
Symposium-Nails Part I
Symposium-Nails-Part II
Systematic Review and Meta-Analysis
Systematic Reviews and Meta-analyses
Systematic Reviews and Meta-analysis
Therapeutic Guideline-IADVL
Therapeutic Guidelines
Therapeutic Guidelines - IADVL
Therapy Letter
Therapy Letters
View Point
What’s new in Dermatology
View/Download PDF

Translate this page into:

Residents Corner
doi: 10.4103/0378-6323.55424
PMID: 19736458

Autologous serum skin test: Methodology, interpretation and clinical applications

Surbhi Vohra, Nand Lal Sharma, Vikram K Mahajan
 Department of Dermatology, Venereology and Leprosy, Indira Gandhi Medical College, Shimla, India

Correspondence Address:
Nand Lal Sharma
Department of Dermatology, Venereology and Leprosy, Indira Gandhi Medical College, Shimla 171001 (H.P.)
How to cite this article:
Vohra S, Sharma NL, Mahajan VK. Autologous serum skin test: Methodology, interpretation and clinical applications. Indian J Dermatol Venereol Leprol 2009;75:545-548
Copyright: (C)2009 Indian Journal of Dermatology, Venereology, and Leprology


Autoimmune urticaria, a recently described subset of chronic urticaria, has often severe and continuous whealing associated with malaise, indigestion and sensation of hot and cold. A personal or family history of other autoimmune diseases or urticaria in family members is suggestive. It is associated with antithyroid antibodies in 27% of patients or with other autoimmune conditions such as vitiligo, rheumatoid arthritis, pernicious anemia and insulin-dependent diabetes mellitus. [1],[2] Diagnosing these patients becomes important as they need high doses of antihistamines and systemic corticosteroids during acute exacerbations. Immunomodulatory drugs, while their use is not justified in chronic idiopathic urticaria (except in antihistamine refractory chronic urticaria cases), are therapeutic benefit in recalcitrant to therapy autoimmune urticaria patients having significantly impaired quality of life. [3] Immunologically, it is characterized by the presence of functional autoantibodies that activate mast cells and basophils by crosslinking the high-affinity IgE receptor (FceRI). About 50% patients of chronic urticaria have functional autoantibodies to FceRI and 9% to the IgE antibody itself. [4],[5] Autoimmune urticaria is thus diagnosed in ASST-positive chronic urticaria patients who exhibit functional autoantibodies against IgE and/or its high-affinity receptor FceRI. However, it is often clinically difficult to distinguish chronic urticaria from autoimmune urticaria. Its diagnosis is practically relied upon clinical suspicion and autologous serum skin test (ASST) as facilities for assaying functional histamine release from basophils or mast cells, a suitable diagnostic laboratory investigation, are largely confined to research centers. Unfortunately, the immunoblot assays, for binding of autoantibody to autoantigen, have not shown any correlation with basophil histamine release and attempts to develop a suitable enzyme-linked immunosorbent assay (ELISA) for clinical use to differentiate between functional and nonfunctional autoantibodies too has remained unsuccessful. Therefore, it becomes imperative for all practising dermatologists to know the precise methodology, accurate interpretation and clinical applications of ASST for effective management of autoimmune urticaria patients.


Historically, in 1986, Grattan et al. [6] were the first to use ASST to differentiate autoimmune urticaria from chronic idiopathic urticaria. They injected intradermally 0.1 ml of autologous serum and normal saline as control in 12 patients of chronic idiopathic urticaria. The positive results were arbitrarily defined as formation of a wheal by serum within 2 h of injection that is at least 5 mm larger than that resulting from saline control and had a difference of 10 mm in the diameter of surrounding erythema. They observed positive responses in 7 patients within 30 min which attained their zenith in 90-120 min and remained positive for an average of 8 h. Subsequently, Sabroe et al. [7] standardized its methodology and defined the parameters which provide optimum sensitivity and specificity for detecting patients of chronic urticaria with autoantibodies [Table - 1]. [4] There have been numerous modifications in the methodology and interpretation of ASST since then in various studies. O′Donnell et al. [8],[9] from their two separate studies interpreted positive ASST as the mean diameter of serum-induced wheal being at least 2 mm larger than that of saline-induced wheal at 30 min. Bakos and Hillander [10] used 0.1 ml instead of 0.05 ml each of serum, histamine and saline. Toubi et al. [11] also used 0.1 ml of sterile autologous serum and determined the wheal/flare size at 30 min and followed up for 60 min and graded the responsed from 0 to +3 of ASST by measuring wheal/flare diameter as 0 = negative control; +1 = wheal 1.5 mm > negative control, flare 15 mm; +2 = wheal 3-5 mm > negative control, flare > 15 mm; +3 = wheal 6-10 mm > negative control.

As ASST results tend to get modified with treatment, the patients should be off antihistamines for at least 2-3 days (long-acting antihistamine for 7 days) and doxepin for 2 weeks prior to the test to avoid false negative results. [7],[12],[13] Most studies also exclude patients taking corticosteroids or immunosuppressive agents during the foregoing 6 weeks to 3 months of ASST.[7],[14] In other words, the patient should have active disease at the time of ASST. However, the test is not performed over areas involved by wheals in the last 24 h.

Preparation of Autologous Serum and Controls

Two milliliters of patient′s venous blood is collected in a sterile glass tube and allowed to clot for 30 min at room temperature. The serum is then separated by centrifugation at 500× g for 15 min and used immediately for ASST. [12],[13]

Histamine diphosphate 10 µg/ml for positive control and sterile physiological saline (0.9%) for negative control are used. [12],[13]

Procedure and Interpretation

Approximately 0.05 ml (equivalent to 2 units on insulin syringe that has 1 ml marked as 40 units) each of autologous serum, histamine diphosphate and sterile physiological saline is injected separately intradermally over volar aspect of the left forearm.[1],[4],[12],[15] Every time a separate syringe should be used for each solution. Autologous serum is injected most proximally and histamine more distally with normal saline in the middle keeping a gap of at least 5 cm between the two injection sites. After 30 min (15 min for histamine), the wheal formed at each injection site is measured at two perpendicular diameters (d 1 and d 2 ) and the average of the two is calculated. [1],[4],[12],[15] Wheal area can also be calculated according to the formula ð [(d1 +d 2 ) 2 /4].[2] If needed the wheal volume can be calculated by multiplying the wheal area by half the change in skin-fold thickness measured with a low-tension spring-loaded thickness measuring gauge. The surrounding flare is often ignored but the redness response is measured as ′ redness score[Table - 2]. [4]

Positive ASST is the one with serum-induced wheal which has both redness score = 2 and a diameter (average of d 1 and d 2 ) of ≥1.5 mm as compared to the saline-induced wheal at 30 min [Figure - 1]. Using this criterion, the sensitivity and specificity of the ASST for detecting autoantibodies is 70 and 80%, respectively, and false positive results in healthy subjects and controls are minimal.

Clinical Relevance

The reported prevalence of ASST positivity in patients of chronic urticaria varies from 35 to 58% in various studies. [6],[8],[9],[10],[16] Autologous serum skin test (ASST) positivity has been found to correlate well with the severity and duration of attacks of urticaria. [11],[17] However, it needs to be kept in mind that positive ASST does not specifically imply mast cell degranulation by autoimmune stimulation as a cause of the wheal response. It rather helps to define a subgroup of patients with chronic urticaria who are most likely to have endogenous cause and the results must be interpreted in the context of clinical relevance.


Despite being the most accessible and useful test for demonstrating endogenous vasoactive factors in the patient′s blood with chronic idiopathic urticaria, a positive ASST is not synonymous to autoimmune urticaria. The significance of a negative ASST also remains less clear. For instance, the reported prevalence of positive ASST in chronic urticaria is about 60% while IgG antibodies specific for the high-affinity IgE receptor FceRI or IgE are detected in not more than 30−40% of ASST-positive patients. [18] This signifies that different histamine-releasing factors, some chemokine-like, may be involved in vivo, and that such factors may also be clinically relevant in ASST-negative patients. Validity of ASST also remains questionable in view of the findings of a recent study by Bajaj et al ., [19] wherein they used autologous serum therapy in ASST-positive and ASST-negative chronic urticaria patients and could prevent relapse almost equally well in both the groups for as long as 2 years suggesting existence of a subset of ASST-negative autoimmune urticaria patients. They suggested that the ASST positivity perhaps reflects an autoreactive state to multiple and yet to be identified circulating factors in the patient′s own blood. It is probable that the ASST-negative patients possess a different IgG subclass with decreased ability to release histamine from basophil activation. Although all these may partly be explained on the basis of results being false negative in ASST-negative autoimmune urticaria patients, future studies may unravel these aspects.

Autologous serum skin test (ASST) is also not bereft of limitations. Although it may not hold true in all cases, a positive ASST has been demonstrated to be associated with the presence of H. pylori antibodies. [14],[20] Interestingly its reactivity also correlates strongly in patients who have multiple intolerances to nonsteroidal antiinflammatory drugs. [21] It is time-consuming, needs expertise for reproducibility, stopping antihistamines prior to the test in severe cases may be difficult, testing over the site of recent wheals may alter the results and the results may sometimes need to be correlated with in vitro basophil histamine-release assays. [4],[5] There are also health and safety issues involved in relation to the preparation of autologous serum. Nevertheless, ASST offers a simple screening test for potentially relevant biological activity and may help to define a subgroup of patients with urticaria who are more likely to have an endogenous cause for their disease than do patients without a positive test. It has good sensitivity and even better sensitivity in detecting autoantibodies in children as well. [22] Therefore, it can reasonably be used as a predictive clinical test to diagnose autoimmune urticaria, especially in situations where the basophil histamine-releasing test is not available.

Kaplan AP. Chronic urticaria: Pathogenesis and treatment. J Allergy Clin Immunol 2004;114:465-74.
[Google Scholar]
Grattan CE, Sabore RA, Greaves MA. Chronic urticaria. J Am Acad Dermatol 2002; 46:645-7.
[Google Scholar]
Inamadar AC, Palit A. Management of autoimmune urticaria. Indian J Dermatol Venereol Leprol 2008;74:89-91.
[Google Scholar]
Grattan CEH. Autoimmune urticaria. Immunol Allergy Clin N Am 2004;24:163-81.
[Google Scholar]
Sabroe RA, Greaves MW. Chronic idiopathic urticaria with functional autoantibodies: 12 years on. Br J Dermatol 2006;154:813-19.
[Google Scholar]
Grattan CEH, Wallington TB, Warin RP, Kennedy CTC, Bradfield JW. A serological mediator in chronic idiopathic urticaria: A clinical, immunological and histological evaluation. Br J Dermatol 1986;114:583-90.
[Google Scholar]
Sabroe RA, Grattan CEH, Francis DM, Barr RM, Black AK, Greaves MW. The autologous serum skin test: A screening test for autoantibodies in chronic idiopathic urticaria. Br J Dermatol 1999;140:446-52.
[Google Scholar]
O'Donnell BF, Nell CMO, Francis DM, Niimi N, Barr MR, Barlow RJ, et al . Human leucocyte antigen class II associations in chronic idiopathic urticaria. Br J Dermatol 1999; 140:853-58.
et al . Human leucocyte antigen class II associations in chronic idiopathic urticaria. Br J Dermatol 1999; 140:853-58.'>[Google Scholar]
O'Donnell BF, Francis DM, Swana GT, Seed PT, Kobza BA, Greaves MW. Thyroid autoimmunity in chronic urticaria. Br J Dermatol 2005;153:331-35.
[Google Scholar]
Bakos N, Hillander M. Comparison of chronic autoimmune urticaria with chronic idiopathic urticaria. Int J Dermatol 2003;42:613-15.
[Google Scholar]
Toubi E, Kessel E, Avshovich N, Bamberger, Sabo E, Nusem D, et al . Clinical and laboratory parameters in predicting chronic urticaria duration: A prospective study of 139 patients. Allergy 2004;59:869-73.
[Google Scholar]
Kulthanan K, Jiamton S, Gorvanich T, Pinkaew S. Autologous Serum Skin Test in Chronic Idiopathic Urticaria: Prevalence, Correlation and Clinical Implications. Asian Pacific J Allergy Immunol 2006;24:201-6.
[Google Scholar]
Godse KV. Autologous serum skin test in chronic urticaria, Indian J Dermatol Venereol Leprol 2004;70:283-4.
[Google Scholar]
Baskan BE, Turker T, Gülten M, Tunali S. Lack of correlation between Helicobacter pylori infection and autologous serum skin test in chronic idiopathic urticaria. Int J Dermatol 2005;44:993-5.
[Google Scholar]
Sabroe RA, Seed PT, Francis DM, Barr RM, Black AK, Greaves MW. Chronic idiopathic urticaria: Comparison of the clinical features of patients with and without anti-Fc ep-silon RI or anti-IgE autoantibodies. J Am Acad Dermatol 1999;40:443-50.
[Google Scholar]
Sabroe R, Fiebiger E, Francis D, Maurer D, Seed P, Grattan C, et al . Classification of anti FceRI and anti-IgE autoantibodies in chronic idiopathic urticaria and correlation with disease severity. J Allergy Clin Immunol 2002;110:492-99.
[Google Scholar]
Fusari A, Colangelo C, Bonifazi F, Antonicelli L. The autologous serum skin test in the follow-up of patients with chronic urticaria. Allergy 2005;60:256-58.
[Google Scholar]
Riboldi P, Riccardo R, Tedeschi A, Gerosa M, Meroni PL. Chronic Urticaria: New Immunologic Aspects. Isr Med Assoc J 2002;4:872-3.
[Google Scholar]
Bajaj AK, Saraswat A, Upadhyay A, Damisetty R, Dhar S. Autologous serum therapy in chronic urticaria: Old wine in a new bottle. Indian J Dermatol Venereol Leprol 2008;74: 109-13.
[Google Scholar]
Hizal M, Tuzun B, Wolf R, Tuzun Y. The relationship between Helicobacter pylori IgG antibody and autologous serum skin test. Int J Dermatol 2000;39:443-5.
[Google Scholar]
Erbagci Z. Multiple NSAID intolerance in chronic idiopathic urticaria is correlated with delayed, pronounced and prolonged autoreactivity. J Dermatol 2004;31:376-82.
[Google Scholar]
Godse KV. Autologous serum skin test in children. Indian J Dermatol 2008;53:61-3.
[Google Scholar]

Fulltext Views

PDF downloads
Show Sections