Allergy : Corticosteroid

• Although allergic reactions to corticosteroids do occur, they are, in the vast majority of times, due to intravenous or intramuscular injection.
• Patients can also develop hypersensitivity reactions to nasal, inhaled, oral, and parenteral CS

Systemic Steroids:

• reactions occur more frequently in asthmatic subjects and in patients regularly treated with systemic CSs(e.g. in the case of a missing or transplanted kidney) than in other subjects. 
• However, in these cases, it is difficult to determine whether the higher incidence of allergies observed is due to increased susceptibility, or to greater exposure to CSs.
• Other factors such as hypersensitivity to salicylic acid might also constitute risk factors ; neither can genetic predisposition to CS allergies be excluded
  

Topical Steroids

• The incidence reported in the literature varies between 0.5% to 6%
• People with chronic eczema who require multiple prescriptions of topical steroids are at increased risk of becoming sensitized to topical steroids
• Risk factors for immediate corticosteroids allergy
• Patients requiring repeated doses of steroids e.g., renal transplant patients, severe asthmatics
• Aspirin sensitivity
• Female sex
• Risk factors for allergic contact dermatitis (delayed hypersensitivity) to corticosteroids
• Chronic nonhealing dermatitis / eczema
• Stasis dermatitis
• Chronic hand eczema
• Having allergic contact dermatitis to other chemicals

Cross Reactivity

• There is an antigenic classification of corticosteroids based on their cross-reactivity related to contact dermatitis reactions. 
• Although this deals with delayed hypersensitivity, it could perhaps give one a guide as to what corticosteroid might exhibit the least chance of cross-reacting with 
• Corticosteroids with lower risk of sensitization
• Group C,
• The metylated and halogenated members of Group D,
• Newer synthetic steroids like Fluticasone propionate (cutivate) and mometasone furorate (Elocon) have a lower risk of sensitization

References:

1. http://www.allergyclinic.co.nz/corticosteroid_allergy.aspx
2. https://www.aaaai.org/ask-the-expert/allergic-reaction-prednisone
3. https://www.ncbi.nlm.nih.gov/pubmed/23567983
4. https://www.ncbi.nlm.nih.gov/pubmed/11456363
5. Allergic hypersensitivity to topical and systemic corticosteroids:
   a review. 2009 John Wiley & Sons A/S Allergy 2009: 64: 978–994