Topicals

Antibiotics

The most common topical antibiotics which cause ACD are those found in triple antibiotic ointment—neomycin, polymyxin B, and bacitracin (Choi et al. 2021).

Important

Of patients with neomycin ACD, 50% will cross-react with other aminoglycosides such as gentamicin.

Anesthetics

The most common topical anesthetics which cause ACD are lidocaine and benzocaine.

Note

While patch testing can confirm ACD due to a local anesthetic, not all patients will necessarily develop an allergic reaction to the same anesthetic if used intradermally or subcutaneous—which is often done for dental and dermatologic procedures.

Corticosteroids

Most patients with ACD secondary to corticosteroids have a history of atopy. Because corticosteroids are often not considered initially as a possible cause of ACD, there might be increased use and worsening of a patient’s dermatitis.

ACD due to corticosteroids may produce an “edge effect” or “doughnut-type” reaction–due to the anti-inflammatory effect of the higher concentration of the corticosteroid in the central area compared to the periphery.

Important

If a patient has ACD due to a topical corticosteroid, you should consider propylene glycol as a potential cause—an excipient found in various topical corticosteroids and one of the top 4 causes of ACD due to drugs.

Propylene Glycol

Propylene glycol—an excipient—may be utilized in topical drugs as a softening agent, solvent, moisturizer, or preservative.

Of patients with propylene glycol ACD, 80% have a history of atopic dermatitis.

Important

Propylene glycol is present in various topical emolients, corticosteroids, and calcineurin inhibitors (Tran and Reeder 2020).

Table 1: Select topical drugs for treatment of atopic dermatitis by propylene glcyol content.
Topical Propylene glycol-containing Propylene glycol-free
Emolients
Corticosteroids
  • Mometasone furoate ointment 0.1%

  • Triamcinolone acetonide ointment 0.1%

  • Hydrocortisone ointment 2.5%
Calcineurin inhibitors
  • Pimecrolimus cream 1%
  • Tacrolimus ointment 0.03% and 0.1%

Eye Drops

The eyelids are more susceptible to ACD compared to other facial areas—owing to their thin skin 0.55 mm compared to 2 mm, respectively (Amin and Belsito 2006). Therefore, the eyelids may be the only affected area by a drug that comes in contact with the face.

Note

ACD due to eye drops is primarily caused by anti-microbial preservatives rather than the primary drug. Benzylalkonium chloride is the most commonly implicated preservative in patients with history of eye drop reactions (Dear, Palmer, and Nixon 2021).

Table 2: Select commercially-available eye drops for common treatment categories by benzylalkonium chloride content
Category Benzyalkonium chloride-containing Benyzlalkonium chloride-free
Antibiotic

  • Ciprofloxacin (Ciloxan)

  • Gatifloxacin (Zymar)

  • Neomycin/Polymyxin B sulfates/Dexamethasone (Maxitrol)

  • Ofloxacin (Ocuflox)

  • Polymyxin B sulfate/Trimethoprim (Polytrim)

  • Tobramycin (Tobrex)

  • Moxifloxacin (Vigamox)

  • Erythromycin ointment (Ilotycin)
Corticosteroid

  • Dexamethasone (Maxidex)

  • Prednisolone acetate

  • Prednisolone sodium phosphate
  • Loteprednol 0.5% ointment
NSAID

  • Keterolac 0.4% (Acular LS)

  • Ketorolac 0.5% (Acular)
  • Keterolac 0.45% (Lotemax)
Gluacoma

  • Brinzolamide (Azopt)

  • Timolol (Timoptic)

  • Tafluprost (Zioptan)

  • Latanoprost (Iyuzeh)

  • Timolol (Timoptic in Ocudose)

  • Dorzolamide/Timolol (Cosopt PF)

References:

https://eyewiki.org/Preservatives_in_Topical_Ophthalmic_Medications#Benzalkonium_chloride_(BAK)