Introduction

Acne vulgaris is a highly prevalent inflammatory skin disease affecting adolescents and adults, often causing significant psychosocial burden. Topical clindamycin 1% is an established treatment; however, rising antibiotic resistance has created a need for alternative therapies. Dapsone 5% gel possesses both antimicrobial and anti-inflammatory properties and may offer effective acne control with minimal systemic exposure.

Aim

• To compare the efficacy and safety of topical dapsone 5% gel versus topical clindamycin 1% gel in patients with mild-to-moderate facial acne vulgaris. 

Patient Profile

• Patients with facial acne vulgaris
• Aged 14-40 years 
• Investigator's Static Global Assessment (ISGA) score ≥1 and <4

Methods

• Prospective, randomized, double-blind clinical trial. 
• Total 80 patients (40 per treatment group) were enrolled 
  • Group 1: Topical clindamycin 1% gel
  • Group 2: Topical dapsone 5% gel
• Treatment duration: 12 weeks with once-daily nighttime application 
• Efficacy assessments
  • ISGA         scores at baseline and at 4, 8, and 12 weeks

Grade	Clinical Description
0	Clear skin, no acne lesions
1	Nearly clear skin, few lesions
2	Mild acne with several comedones and few inflammatory lesions
3	Moderate acne with numerous lesions and few nodules
4	Severe acne with many inflammatory lesions including nodules

 

Reduction in TLC	Response Category
<25%	Mild improvement
25-50%	Moderate improvement
51-75%	Significant improvement
>75%	Excellent improvement

 

• Safety assessment included Adverse Drug Reactions (ADRs) 
• Quality of life assessment: Cardiff Acne Disability Index (CADI) 

Results

• 75 patients (37 in clindamycin group, 38 in dapsone group) completed the study

• Both treatments significantly improved acne severity over 12 weeks, with comparable reductions in ISGA scores and total lesion counts at all follow-up points (4, 8, and 12 weeks), the differences between groups were not statistically significant (p>0.05), and both groups showed consistent improvement over time.
• By 12 weeks, ISGA scores were comparable (Table 1)

Table 1. ISGA Score Improvement

Time Point	Clindamycin 1% (Mean)	Dapsone 5% (Mean)	p Value
Baseline	2.81	2.65	0.003
Week 4	2.32	2.50	0.465
Week 8	1.78	1.55	0.683
Week 12	1.189	1.184	0.913

 

• Both groups achieved substantial reductions in total lesion count, with no significant difference between treatments (p = 0.148)
• Reduction in non-inflammatory lesions (comedones) was similar in both groups
• Topical dapsone demonstrated significantly greater effectiveness in reducing inflammatory lesions. Group 2 consistently showed a more pronounced reduction in papules from 4 weeks onward, with a notably lower mean count at 12 weeks (p=0.001). Similarly, pustule counts were significantly lower in group 2 at all follow-up points.

Table 2: Mean of Inflammatory Lesion Reduction During the Study Period

Lesion Type	Treatment	Baseline	Week 4	Week 8	Week 12	p Value (Week 12)
Comedones	Clindamycin 1%	14.32	9.72	6.40	4.43	0.941
	Dapsone 5%	14.26	9.15	5.76	4.07
Papules	Clindamycin 1%)	27.67	8.45	5.86	4.97	0.001
	Dapsone 5%	28.97	10.26	8.15	0.65
Pustules	Clindamycin 1%	4.56	2.05	0.20	1.91	<0.001
	Dapsone 5%	3.18	0.52	0.63	0.65

 

• Excellent TLC reduction (>75%) achieved in 43.2% of clindamycin-treated patients and 68.4% of dapsone-treated patients.

Table 3. TLC reduction at Week 12

	Percentage of patients
Response Category	Clindamycin	Dapsone
Mild improvement (<25% reduction)	0	0
Moderate improvement (25-50% reduction)	0	0
Significant improvement (51-75% reduction)	56.7%	31.6%
Excellent improvement (>75% reduction)	43.2%	68.4%

 

Safety 

• In Clindamycin Group, 40.54% of patients reported adverse drug reaction of which Erythema was the most frequently observed.
• In Dapsone Group,50% of patients reported ADR. Dryness and irritation were the predominant side effects.
• Dapsone showed a significant improvement in CADIscores at 12 weeks, with outcomes comparable to clindamycin (p = 0.213).

Conclusion

• Topical dapsone 5% gel demonstrated efficacy comparable to topical clindamycin 1% gel for mild-to-moderate acne vulgaris.
• Dapsone provided superior reduction of inflammatory lesions while maintaining a similar safety profile and improving quality of life. 

Reference

Int J Basic Clin Pharmacol. 2025;14(5):733-738.