Evidence‑Based Management of Axillary and Inguinal Hyperpigmentation

Risks Associated with Hydroquinone‑Containing Products

Hydroquinone 4 % can cause irritation and contact dermatitis, and in darker skin types may lead to exogenous ochronosis; these risks are amplified in friction‑prone intertriginous areas. Low‑quality observational evidence. 1

Glycolic acid 20 % applied every 2 weeks produces a statistically significant reduction in axillary hyperpigmentation, with visible improvement typically observed within 8–12 weeks. Moderate‑quality evidence (randomized/controlled trial). 4
Initiate treatment with applications every 4 weeks to assess tolerance; if tolerated, increase to every 2 weeks and maintain at intervals of 2–4 weeks based on clinical response. Moderate‑quality evidence. 4
Strict daily photoprotection with SPF 30+ broad‑spectrum sunscreen and protective clothing is required because glycolic acid (and concomitant retinoids) increase photosensitivity. Moderate‑quality evidence. 4

The most common adverse effects of glycolic acid (and adjunctive tretinoin) are irritation, erythema, desquamation, burning, and excessive dryness; therapy should be stopped immediately if hypersensitivity reactions develop. Moderate‑quality evidence. 4

Desonide 0.05 % applied short‑term (≤ 2 months) yields significant improvement in axillary hyperpigmentation with minimal side‑effects, making it a viable adjunct when chemical exfoliation alone is insufficient. Moderate‑quality evidence (controlled trial). 5

Axillary and inguinal hyperpigmentation is frequently chronic and recurrent, necessitating long‑term maintenance strategies to sustain results. Expert‑opinion/level III evidence. 6
Clinically meaningful improvement generally becomes apparent after 8–12 weeks of appropriate therapy. Moderate‑quality evidence. 6, 7