Can Infections Trigger Psoriasis Flares?

Psoriasis is a chronic autoimmune skin condition that affects millions worldwide. Characterised by red, scaly, and itchy patches, it can range from mild to severe, impacting both physical and emotional well-being. While genetics and immune system factors are central to psoriasis, environmental triggers often play a significant role in flares—periods when symptoms suddenly worsen. Among these triggers, infections are a major, sometimes overlooked, factor.

Understanding Psoriasis and Flares

Psoriasis occurs when the immune system becomes overactive, accelerating the lifecycle of skin cells. Normally, skin cells take about a month to regenerate, but in psoriasis, this process can occur in just a few days, leading to the buildup of scaly plaques.

A psoriasis flare is defined as a sudden worsening of symptoms. Common flare triggers include:

-Stress and emotional strain

-Weather changes (cold, dry air)

-Certain medications (like beta-blockers or lithium)

-Infections

How Infections Trigger Psoriasis

Infections, whether bacterial, viral, or fungal, can activate the immune system, which in turn may exacerbate psoriasis. The connection is most clear in specific types of psoriasis:

1. Guttate Psoriasis and Strep Infections
   Guttate psoriasis often appears as small, drop-like red patches. It commonly occurs after streptococcal throat infections. The immune response to the bacteria can inadvertently target skin cells, triggering a flare within 2–3 weeks after the infection.

2. Viral Infections
   Viruses, including the common cold, influenza, and even COVID-19, can provoke immune system activation, potentially worsening plaque psoriasis. Some patients notice flares during or shortly after viral illnesses.

3. Skin and Fungal Infections
   Local skin infections, such as staphylococcal infections, or fungal infections like tinea, can also aggravate psoriatic lesions. The inflammation and immune activation around the infection site may extend to psoriasis plaques.

4. Systemic Infections
   Severe infections that stress the body’s immune system, including urinary tract infections or pneumonia, can indirectly trigger flares by increasing systemic inflammation.

The Immune System Connection

Psoriasis is fundamentally an immune-mediated disease, involving T-cells and cytokines like TNF-alpha, IL-17, and IL-23. When the body fights an infection, these immune pathways can become hyperactivated. For people with psoriasis, this immune response can unintentionally attack skin cells, leading to rapid plaque formation and flare-ups.

Recognising Infection-Triggered Flares

Signs that an infection may have triggered a psoriasis flare include:

-Sudden appearance of guttate, small drop-shaped lesions

-Flare occurring after a sore throat, fever, or other infection

-Worsening of existing plaques during or shortly after illness

-Mild itching or irritation accompanying a recent bacterial or viral infection

Managing Psoriasis Flares Triggered by Infections

1. Treat the Underlying Infection
   Prompt treatment of bacterial or fungal infections can reduce immune overactivation and help prevent flare worsening. For example, antibiotics for strep throat can sometimes prevent guttate psoriasis from progressing.

2. Maintain Regular Psoriasis Care
   Continue prescribed topical treatments, moisturizers, and any systemic therapies. Ignoring psoriasis treatment during an infection flare can make lesions worse.

3. Avoid Triggers During Illness
   Stress, dehydration, and poor sleep can worsen flares. Managing these factors during an infection may help mitigate psoriasis severity.

4. Consult a Dermatologist
   If flares are severe, persistent, or rapidly spreading, a dermatologist may recommend phototherapy, biologics, or systemic medications to control inflammation.

Prevention Tips

-Wash hands frequently and avoid exposure to infections when possible.

-Address sore throats or respiratory infections promptly.

-Keep psoriasis well-managed to reduce susceptibility to flares.

-Consider vaccination for preventable infections (flu, COVID-19), especially if psoriasis is treated with immunosuppressive medications.

Bottom Line

Infections are a significant trigger for psoriasis flares. While the link is most evident in guttate psoriasis following strep infections, bacterial, viral, and fungal infections can all provoke immune responses that worsen psoriasis. Understanding this connection empowers patients to act early, treat infections promptly, and manage flares more effectively.

By combining infection control, consistent skincare, and medical management, people with psoriasis can significantly reduce flare frequency and severity, improving both skin health and quality of life.