Derma Unplugged 2.0: The Connection Between HS and Psoriasis

Medical research is increasingly examining the relationship between hidradenitis suppurativa (HS) and psoriasis, two chronic inflammatory skin conditions that can co-occur in the same patient. While the exact nature of the association remains unclear, emerging data suggest a significant overlap in risk factors and biological pathways.

Hidradenitis suppurativa typically affects areas such as the armpits, groin, buttocks, and under the breasts. In contrast, psoriasis is characterized by scaly patches of skin and can also affect the nails, and joints.

Epidemiological Links and Risk Factors

Recent studies have indicated that individuals with one of these conditions may face a higher risk of developing the other. A 2022 systematic review involving more than 560,000 participants across seven studies found that people with hidradenitis suppurativa were 2.67 times more likely to have psoriasis than those without HS.

Conversely, a large-scale population study of 68,836 people with psoriasis and 68,836 controls estimated that those with psoriasis have an 80% increased risk of developing hidradenitis suppurativa compared to those without the condition.

Research from a 2023 review suggests that approximately 9% of people with HS have plaque psoriasis, while 11% have palmar-plantar pustulosis, a specific type of psoriasis affecting the palms of the hands and soles of the feet.

Both conditions share several common risk factors, including:

• Obesity
• Smoking
• Genetic susceptibility and hereditary predisposition

Biological Overlap and Treatment Challenges

The connection between HS and psoriasis may be rooted in shared inflammatory pathways. Experts have noted the central role of specific cytokines in both diseases, specifically TNF-alpha, IL-17, and IL-23.

Managing a dual diagnosis can be complex because the two conditions may require different treatment approaches, which can significantly impact a patient’s quality of life.

Some research has also explored the impact of medication on this relationship. A 2023 narrative review found that some patients with psoriasis who began biologic therapy may develop drug-induced hidradenitis suppurativa.

Current Scientific Consensus and Uncertainties

Despite the observed co-occurrence, a causal relationship has not been firmly established. A 2023 publication in Front Med (Lausanne) noted that while several case reports suggest a causal link, firm epidemiological data are still lacking.

The global prevalence of hidradenitis suppurativa is estimated to affect between 0.00033% and 4.1% of the population, with 0.7% to 1.2% of cases occurring within European and U.S. Populations.

Further research is required to fully elucidate the exact relationship between these two inflammatory skin diseases and to determine how their shared biological markers can be better targeted for treatment.