Penicillium chrysogenum
Allergy Facts, Symptoms, and Treatment

Penicillium Chrysogenum

Penicillium is among the top three most common indoor airborne fungi (along with Aspergillus and Cladosporium).1,2 These same three molds as well as Alternaria alternata are the species most likely to cause allergy symptoms, which typically occur after allergic individuals inhale mold spores.3,4 Perhaps most familiar, however, is the Penicillium chrysogenum species, which is typically blue-green in color and can be found both indoors and outside.2

One of six species most commonly found in water-damaged environments, this mold is also a source of antibiotics such as penicillin.1,5 Closely associated with asthma, P. chrysogenum is well known as both an allergen and a pathogen (i.e., something that causes disease), and particularly in those with weakened immune systems due to an existing illness, it can trigger a variety of infections.5 Penicillium spores can be detected in the air throughout the year, but they can also show seasonal fluctuations. For example, in the United Kingdom, spores reach their peak in autumn, with highest levels during daytime hours.6

Where is Penicillium found?

Penicillium chrysogenum is widespread in temperate and subtropical regions and is present practically anywhere organic material is available.4,5 Penicillium can be found outdoors in mediums such as soil, decaying plant debris, compost, grains, and rotting fruit.4 However, mold reproduces via spores, which can be transported by air, water, and insects.7,11 So even if a fungus originates outdoors, it often can enter your home through a variety of means, including doorways, windows, vents, and heating and air conditioning systems. Plus, it can hitch a ride inside via clothing, shoes, and pets.12 Therefore, Penicillium is also found indoors, where it usually grows on surfaces such as drywall, wood, painted materials, wallpaper, carpet, paint, fabrics, dust, and various other household contents.13,14 Plus, it sometimes colonizes leather products such as shoes, jackets, belts, and sofas. Penicillium chrysogenum can also develop on foods such as fruits and vegetables, cereal grains, cured meat, margarine, cheese, and other dairy products.5

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Are there other allergens I could be sensitized to?*

Some people with Penicillium chrysogenum allergy may also experience symptoms when exposed to other types of mold. This is called cross-reactivity and occurs when your body's immune system identifies the proteins, or components, in different substances as being structurally similar or biologically related, thus triggering a response.2

*These products may not be approved for clinical use in your country. Please work with your healthcare provider to understand availability.

How do I manage my allergy?

If you are allergic to mold, your healthcare provider may recommend a plan that includes the following.3,7,16,17

  • Limit your outdoor time during seasons when mold is most active.
  • Wear a mask when disturbing or moving plant materials, and avoid raking and burning dry leaves.
  • Avoid barns, silos, hay, straw, and peat moss.
  • Use a certified asthma and allergy friendly filter attachment on your heating and air conditioning unit, and change filters regularly.
  • Employ dehumidifiers to lower indoor humidity levels to less than 45 percent to create an environment where mold is less likely to thrive.
  • Improve air flow through rooms by opening doors between spaces, moving furniture away from the walls, and operating fans.
  • Use exhaust fans in bathrooms and kitchens to pull moisture out of the rooms.
  • Fix any plumbing leaks, check windows for condensation, and remove sources of dampness.
  • Repair roof leaks, clean gutters, and ensure rainwater drains away from your dwelling.
  • Clean thoroughly and regularly, including sinks and tubs, refrigerator door gaskets, and garbage cans.
  • Remove clothes from washing machines promptly and clean rubber seals regularly.
  • Eliminate sources of dampness in basements, such as pipe leaks and groundwater seepage.
  • Run ventilation fans during and after showers and baths.
  • Remove any carpet from bathrooms and basements.

Your healthcare provider may direct you to take one of the following medications to improve your allergy symptoms:

  • Antihistamines are commonly used to reduce symptoms such as sneezing, itching, and runny nose.
  • Nasal corticosteroids are used to reduce swelling in the nose and block allergic reactions.
  • Oral and nasal spray decongestants can be employed to relieve stuffiness.
  • Anti-inflammatories such as montelukast, which can be effective in treating mold allergy.
  • Daily nasal lavage using a squeeze bottle filled with salt water can help clean out irritants and alleviate nasal symptoms.

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Common Symptoms

Mold allergy symptoms can range from mild to severe and vary person to person.3 Reactions can happen almost immediately after exposure, or they can be delayed. Symptoms are most common in mid-summer to early fall, but since molds grow both indoors and out, allergic reactions can occur all year.7

Symptoms typically include one or more of the following:3,8

  • Nasal congestion
  • Runny nose
  • Sneezing
  • Irritated, watery eyes
  • Coughing
  • Wheezing
  • Itchy eyes, nose, and throat
  • Dry, scaly skin

Mold sensitization is also a major risk factor for developing upper and lower respiratory diseases such as allergic rhinitis (aka hay fever).4,9 In addition, other reactions to Penicillium can include hypersensitivity pneumonitis (also known as extrinsic allergic alveolitis), which can lead to a chronic disease with irreversible lung damage.9

A small percentage of asthmatics with inhaled mold allergy can also develop allergic urticaria (aka hives) when they eat or drink anything containing yeast or mold.10 In addition to causing allergic reactions, molds can also lead to infections along with toxic reactions.1

How do I know if I'm allergic?*

Together with your symptom history, skin-prick testing or specific IgE blood testing can help determine if you are allergic to a particular allergen. If you are diagnosed with an allergy, your healthcare provider will work with you to create a management plan.

*These products may not be approved for clinical use in your country. Please work with your healthcare provider to understand availability.

Is there a risk for a severe event?

There are no credible reports in medical literature documenting indoor exposure to molds as a cause of anaphylaxis.15 However, exposure and sensitization to fungal allergens can promote the development and worsening of allergic diseases such as allergic rhinitis and asthma.2

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  2. Fukutomi, Yuma & Taniguchi, Masami. (2015). Sensitization to fungal allergens: Resolved and unresolved issue. Allergology International. 145. 10.1016/j.alit.2015.05.007. Available from:
  3. Mayo Clinic [Internet]. Rochester, MN: Mayo Foundation for Medical Education and Research; 2019 Apr 3. Available from:
  4. Ozdemir O (2015) Molds and Respiratory Allergy - Part 1. MOJ Immunol 2(2): 00045. DOI: 10.15406/moji.2015.02.00045. Available from:
  5. Ward J., Leduc C. Mold Busters [Internet]. Ottowa, ON, Canada: Bust Mold Inc.; 2018 Aug 26 [2019 Apr 20]. Available from:
  6. Knutsen AP, Bush RK, Demain JG, Denning DW, Dixit A, Fairs A, Greenberger PA, Kariuki B, Kita H, Kurup VP, Moss RB, Niven RM, Pashley CH, Slavin RG, Vijay HM, Wardlaw AJ. Fungi and allergic lower respiratory tract diseases. J Allergy Clin Immunol. 2012 Feb;129(2):280-91; quiz 292-3. doi: 10.1016/j.jaci.2011.12.970. PMID: 22284927. Available from:
  7. Asthma and Allergy Foundation of America [Internet]. Arlington, VA: Asthma and Allergy Foundation of America; 2015 Oct. Available from:
  8. American College of Allergy, Asthma & Immunology [Internet]. Arlington Heights, IL: American College of Allergy, Asthma & Immunology; 2018 Apr 23. Available from:
  9. Simon-Nobbe B, Denk U, Pöll V, Rid R, Breitenbach M. The spectrum of fungal allergy. Int Arch Allergy Immunol. 2008;145(1):58-86. doi: 10.1159/000107578. Epub 2007 Aug 20. PMID: 17709917. Available from:
  10. GI Society [Internet]. Vancouver, BC, Canada: Canadian Society of Intestinal Research; 2004 Mar/Apr. Available from:
  11. United States Department of Agriculture [Internet]. [place unknown]: United States Department of Agriculture; 2013 Aug. Available from:,that%20can%20make%20you%20sick.
  12. Centers for Disease Control and Prevention [Internet]. Atlanta, GA: National Center for Environmental Health; 2020 Aug 11. Available from:
  13. Ward J., Leduc C. Mold Busters [Internet]. Ottowa, ON, Canada: Bust Mold Inc.; 2018 Aug 19 [2019 Apr 1]. Available from:
  14. Abbott, S. Molds and other fungi in indoor environments: Summary of biology, known health effects and references. (2003). Available from:
  15. Bush RK, Portnoy JM, Saxon A, Terr AI, Wood RA. The medical effects of mold exposure. J Allergy Clin Immunol. 2006 Feb;117(2):326-33. doi: 10.1016/j.jaci.2005.12.001. Erratum in: J Allergy Clin Immunol. 2006 Jun;117(6):1373. Erratum in: J Allergy Clin Immunol. 2014 Nov;134(5):1217. PMID: 16514772. Available from:
  16. Mayo Clinic [Internet]. Rochester, MN: Mayo Foundation for Medical Education and Research; 2019 Apr 3. Available from:
  17. Nationwide Children s Hospital [Internet]. Columbus, OH: Nationwide Children s Hospital; 1976 [2018 Oct]. Available from: