SKIN 
 

March 2023     Volume 7 Issue 2 
 

(c) 2022 THE AUTHORS. Published by the National Society for Cutaneous Medicine. 743 

COMPELLING COMMENTS 
 

 

At-Home Microneedling of Acral Skin to Increase Percutaneous 
Absorption of Imiquimod 
 

Kate E. Beekman, BS¹, Danielle K. DePalo, MD2, James M. Grichnik, MD, PhD2,3, Lilia M. 
Correa, MD2,3, Jonathan S. Zager, MD1,2 

 
1USF Health, Morsani College of Medicine, Tampa, FL 
2Moffitt Cancer Center, Department of Cutaneous Oncology, Tampa, FL  
3USF Health, Department of Dermatology and Cutaneous Surgery, Tampa, FL 
 

 
 

 
 
Increased thickness of acral skin can reduce 
percutaneous absorption of topical 
imiquimod and hinder development of 
desired inflammatory response,1 presenting 
a challenge to its efficacy in treating acral skin 
malignancies. 
 

 
 
An 85-year-old female patient with a history 
of 1.3mm Breslow depth, non-ulcerated, 
acral lentiginous melanoma of the left plantar 
foot declined standard-of-care surgical re-
excision of persistent malignant melanoma in 
situ (MMIS) at the margins after three prior 
excisions (Figure 1A). As an alternative, she 
underwent a 3-month course of off-label 
topical imiquimod 5% applied 5x weekly per 
Pandit et al.’s protocol.2 
 
The patient previously received a course of 
imiquimod with tretinoin for residual MMIS 
prior to the most recent surgical excision; 
however, desired inflammatory and disease 
response was not achieved. This time, 
multiple steps were taken to increase 
absorption of imiquimod. First, curettage of 

the positive margin was performed in office to 
remove hyperkeratotic stratum corneum. 
Additionally, the patient was instructed to 
purchase an at-home microneedling kit and 
use the device in 3 directions along the 
positive margin for 1 minute prior to each 
imiquimod application. She was also directed 
to occlude the area with plastic wrap 
following application. After the 3-month 
treatment course, no residual pigmentation 
was present. At 12-month follow-up, the 
patient remained without evidence of disease 
(Figure 1B). 
 

 
Figure 1. (A) Left plantar foot site of previous 
invasive melanoma status post 3 surgical 
excisions with persistent residual MMIS at the 6-
9-12 o’clock (medial) margin before imiquimod 
treatment with microneedling. (B) Left plantar foot 
with sustained absence of residual pigmentation 
at 12-month follow-up from completion of 
imiquimod therapy with microneedling. 

 

CLINICAL PROBLEM 

PRACTICE PEARL 



SKIN 
 

March 2023     Volume 7 Issue 2 
 

(c) 2022 THE AUTHORS. Published by the National Society for Cutaneous Medicine. 744 

 
 
While microneedling has been demonstrated 
to improve intradermal penetration of 
imiquimod in vitro,3 it is not always feasible for 
patients to undergo microneedling in clinic 
before each topical therapy application. 
Although at-home microneedling devices are 
unregulated and pose a risk of infection when 
not properly sanitized, risks can be minimized 
with healthcare provider oversight. We have 
found that at-home microneedling can be 
safely performed under physician direction 
and may improve efficacy of imiquimod in 
treating malignancies of acral skin. 
 
Conflict of Interest Disclosures: J.S.Z. has 
advisory board relationships and has received fees 
from with Merck, Novartis, Philogen, Castle 
Biosciences, Pfizer and Sun Pharma. He also 
received research funding from Amgen, Delcath 
Systems, Philogen, Provectus and Novartis. He 
serves on the medical advisory board for Delcath 
Systems. L.M.C. is a consultant for Accutec and a 
consultant and researcher for Novartis 
Pharmaceutical. She also serves on the Advisory 
Board for the Jacinto Convit World Organization and 
the Dermatology Advisory Council for Melanoma 
Research Foundation. J.M.G is a consultant for 
Galileo Group and Canfield Scientific and serves on 
Skin Advisory Board for Regeneron and Dermatology 
Advisory Council for Melanoma Research 
Foundation. He has received clinical trial support 
from Novartis, Eli Lilly, Dermira, Elorac, Boehringer 
and Amgen. 
 
Funding: None 
 
Corresponding Author: 
Jonathan S. Zager, MD, FACS, FSSO 
10920 N. McKinley Drive, Room 4123 
Tampa, FL 33612 
Phone: (813) 745-1085 
Email: jonathan.zager@moffitt.org 

 
 
References: 
1. Nakamura Y, Fujisawa Y. Diagnosis and 

Management of Acral Lentiginous 
Melanoma. Curr Treat Options Oncol. 

2018;19(8):42. Published 2018 Jun 27. 
doi:10.1007/s11864-018-0560-y 

2. Pandit AS, Geiger EJ, Ariyan S, Narayan D, Choi 
JN. Using topical imiquimod for the management 
of positive in situ margins after melanoma 
resection. Cancer Med. 2015;4(4):507-12. Epub 
20150126. doi: 10.1002/cam4.402. PubMed 
PMID: 25620351; PubMed Central PMCID: 
PMC4402064. 

3. Al-Mayahy MH, Sabri AH, Rutland CS, et al. 
Insight into imiquimod skin permeation and 
increased delivery using microneedle pre-
treatment. Eur J Pharm Biopharm. 2019;139:33-
43. doi: 10.1016/j.ejpb.2019.02.006 

  

CONCLUSION