Fuzzy search Optimization in SQL Server

Question

I am trying to optimize the performance of a stored procedure. I have to search two columns with LIKE operator. Here is the lookup table

CREATE TABLE [dbo].[PrincipalDiagnosis](
        [PrincipalDiagnosisID] [int] IDENTITY(1,1) PRIMARY KEY NOT NULL,
        [Code] [varchar](10) NULL,
        [PrincipalDiagnosisDescription] [varchar](3500) NULL,
   )

I have created two independent NONCLUSTERED indexes on [Code] and [PrincipalDiagnosisDescription] columns. Here is the Query of the stored procedure:

SELECT RTRIM(LTRIM(Item)) AS SearchItem
    INTO #SearchItems
    FROM dbo.SplitString(@SearchQuery, ' ')
    WHERE RTRIM(LTRIM(Item))<>''

SELECT TOP (100) PrincipalDiagnosisID, 
    ISNULL(Code +' '+ PrincipalDiagnosisDescription, '') AS Info       
FROM dbo.PrincipalDiagnosis
WHERE EXISTS (
            SELECT 1
            FROM #SearchItems
            WHERE Code LIKE '%'+SearchItem+'%'
            OR PrincipalDiagnosisDescription LIKE '%'+SearchItem+'%'
         )
ORDER BY 2

EXISTS part is taking so much time. In Execution Plan there is table scan of #SearchItems. I am using SQL server 2014 Enterprise edition. I want to optimize this query as much as I can. I will appreciate your valuable suggestions. Thanks! Muhammad