The skin, as the body’s largest organ, plays essential roles, including serving as a protective barrier against pathogens and environmental stressors. Despite its significance, skin diseases are highly prevalent globally, causing considerable physical and psychological distress. Common chronic conditions include psoriasis, atopic dermatitis, ichthyosis, acne vulgaris, and lichen planus.
For centuries, thermal water use—known as balneotherapy—has been a traditional and generally safe approach for managing these conditions. The popularity of balneotherapy continues to grow, supported by recent research highlighting the role of thermal water’s physiochemical, microbiological, immunological, and mechanical properties in skin healing. Despite this interest, the exact mechanisms behind thermal water’s effects remain unclear. This comprehensive review consolidates existing scientific evidence from in vitro and in vivo studies on both the therapeutic and cosmeceutical applications of thermal water.
Key Findings
- Anti-inflammatory, immunomodulatory, and antioxidant effects
Thermal water helps treat various skin conditions and supports cosmetic benefits by influencing immune and neuroendocrine functions and activating immune and antioxidant systems. - Physicochemical and microbial properties
The therapeutic potential of thermal water is closely tied to its composition, especially minerals like magnesium, sulfur, bicarbonates, selenium, and salts. - Effectiveness of sulfurous water
Sulfur-rich thermal water shows notable efficacy in treating skin diseases due to its antiproliferative, keratolytic, antioxidant, antifungal, and anti-inflammatory properties. It suppresses inflammatory cytokines and limits T lymphocyte proliferation. - Clinical evidence for common dermatological diseases
Thermal water is widely accepted in managing psoriasis, atopic dermatitis, ichthyosis, lichen planus, and acne vulgaris, with most research focusing on psoriasis and atopic dermatitis. - Psoriasis
Balneotherapy and hydrotherapy improve symptoms such as erythema, pruritus, and scaling. Studies report reduced PASI scores and improved QoL scores. Mechanisms include the downregulation of inflammatory cytokines (e.g., IL-6, IL-8, IL-17, IL-22, TNF-α), reduced VEGF-A, decreased keratinocyte proliferation, and microbiome modulation. - Atopic dermatitis (AD)
Thermal water improves severity, pruritus, dryness, and skin barrier function. It reduces transepidermal water loss and increases stratum corneum hydration, while also lowering Staphylococcus aureus colonization and modulating enzyme activity and immune responses. Dead Sea climatotherapy similarly improves AD through microbiome impact. - Ichthyosis
Treatment leads to improved DLQI scores and reduced symptoms like itching, erosion, and erythema. However, data remains limited. - Lichen planus
Use of thermal water alleviates itching, erosion, and erythema, and reduces reliance on corticosteroids and analgesics. - Acne vulgaris
Sulfurous thermal water supports acne treatment through keratolytic action, sebum regulation, reduction of Cutibacterium acnes, and inflammation control. Combined treatments with retinoic acid improved desquamation and product tolerability. - Cosmeceutical benefits
Thermal water is used in gels, sprays, creams, and lotions to support hydration, anti-aging, wound healing, and antioxidant protection. Benefits include improved hydration, smoothness, reduced roughness and scaling, enhanced skin barrier function, increased collagen expression, reduced pigmentation, and support against oxidative stress.
Thermal water balneotherapy offers a validated approach for managing multiple skin diseases while showing significant promise in cosmeceutical formulations. Despite its proven benefits, the exact biological mechanisms behind its effects remain largely unresolved. This review uniquely bridges both therapeutic and cosmetic aspects, calling attention to the need for further research. Future studies should explore underrepresented conditions (e.g., vitiligo, melanoma, basal cell carcinoma), examine molecular and microbiome-related mechanisms, and support clinical integration through long-term, standardized trials. This will be key to unlocking the full dermatological potential of thermal water.
Link to the study: https://link.springer.com/article/10.1007/s00484-025-02937-0
