What Is Shellac Allergy

  • Ann Rose Joseph Doctor of Pharmacy - PharmD , Acharya and BM Reddy college of Pharmacy, Bangalore, Karnataka, India.
  • Samreen Noman Masters in Biomedical Sciences from Univerity of of Applied Sciences Bonn-Rhein-Sieg, Germany


Patients with a shellac contact allergy will develop contact dermatitis on areas exposed to the product, such as eyelid dermatitis from mascara or lip irritation (cheilitis) from lipstick. Allergic contact dermatitis often manifests as erythema and swelling, but in severe cases, blisters may occur.

Shellac allergy is a relatively uncommon but important concern for individuals who may come into contact with shellac-containing products. Shellac is a natural resin secreted by the lac bug and is commonly used in various industries, including woodworking, food production, cosmetics, and pharmaceuticals. While many people do not experience any adverse reactions to shellac, some individuals can develop allergies to it.1

What is shellac?

Shellac is a resin derived from the female lac bug, which can be found in India and Thailand. When exposed to air, it hardens and is frequently processed into amber flakes for sale. It's common in cosmetics, furniture sealants, and food glazes. It is not to be confused with 'Shellac nails', a brand of gel nail paint.

Shellac can be found in:

  • Cosmetics, such as mascara, nail polish, lipstick, and hairspray
  • Household products, such as paint primers, furniture, and other wood sealants·        Food and pharmaceutical coating, such as lollies, tablets, and denture binding agents.1

Labelling regulations and terminology:

Labelling regulations and terminology for shellac, a natural resin often used in various applications such as wood finishing, pharmaceuticals, and food, can vary depending on the specific use and the country or region. Here are some common labelling regulations and terminology associated with shellac:

  • Ingredient List: If shellac is an ingredient in a product, it should be listed in the ingredient list. Food products may be labelled simply as "shellac" or specified as "food-grade shellac."
  • E Number (European Union): In the European Union, shellac used as a food glazing agent is identified with the E number E904.
  • Food Glazing Agent: When shellac is used as a food glazing agent, it is typically listed as "shellac" or "confectioner's glaze" on food labels.
  • Pharmaceutical and Cosmetic Labels: In pharmaceuticals and cosmetics, shellac may be listed as an ingredient and should be clearly labelled as such. It may also be referred to as "shellac wax" or "lac resin."
  • Wood Finishing Products: For products used in woodworking and finishing, shellac is often labelled as "shellac flakes" or "shellac resin." The label may also specify the type of shellac, such as "dewaxed shellac" or "blonde shellac."
  • Country of Origin: Labels may include information about the country of origin or the source of the shellac.
  • Allergen Information: If a product contains shellac, it's essential to consider potential allergenicity, although shellac is not a common allergen.
  • Instructions for Use: Labels on shellac-containing products, especially in the case of woodworking or finishing products, may include usage instructions, such as dilution ratios and application methods.
  • Safety Warnings: If there are specific safety precautions or warnings related to the use of shellac products, these should be clearly stated on the label.
  • Environmental Claims: Manufacturers of shellac products may make environmental claims, particularly if the shellac is sourced sustainably. In such cases, the label should comply with regulations related to environmental claims.
  • Product Identification: Wood finishing and woodworking products containing shellac may include product identification, such as batch or lot numbers, to aid in quality control and traceability.

It's important to note that labelling regulations can vary from one country or region to another, and different industries may have specific requirements. Additionally, the terminology and labelling requirements may change over time, so it's crucial for manufacturers and producers of shellac-based products to stay updated with the latest regulations in their target markets and ensure compliance to maintain product safety and consumer trust.2

Understanding shellac allergy

Symptoms and SeverityShellac allergy most commonly manifests itself as changes in the skin of the fingers. The intensity of symptoms varies per case and is determined by the individual's immune system. The following symptoms can be noted during the early stages of an allergy:

  • Rash that is accompanied by severe itching. It is typically localized around the fingertips; however, it can expand deeper along with the hands.
  • Redness of the skin.
  • Edema. The entire hand can swell, but it is more common for segments to enlarge. Their density and size can vary.

If you do not pay attention to allergy therapy at this time, it will progress. The rash develops a vesicular appearance and is eventually replaced by aging spots. It extends from the fingertips to the entire hand's surface. The palms are covered in a rash that is typical of herpes.

  • The skin in areas of severe irritation coarsens and splits over time, and weeping eczema can occur.
  • Blood rushes through the veins in areas of oedema on the skin, raising their temperature. The nail plate peels off, and the skin around it gets irritated, but the nails suffer the most.
  • Aside from a cutaneous reaction, pulmonary failure is possible. It happens as a result of a person inhaling methacrylate vapours. In moderate cases, symptoms include sneezing, a runny nose, and a sore throat.3

Causes and risk factors

  1. Nail polish:  A coat of nail polish. Surprisingly, eyelid rashes are frequently induced by substances that are not directly applied to the eyelids. A chemical used in nail polish is a common example. Tosylamide formaldehyde resin is a substance that can cause allergic rashes on the eyelids, face, neck, and chest.
  2. Hair Dye: There has undoubtedly been a cultural shift in the last few decades. Both men and women hide their grey hair at an earlier age, and they use hair dye far into their retirement years. I'm also seeing a lot of allergic reactions to hair dye. That takes me to a widespread misunderstanding concerning allergic reactions. Many of my patients tell me that they've been using a product for years and that it's not the source of their allergies.
  3. Artificial nails: Gel and shellac nails can cause adverse responses similar to artificial nails. This is due to the fact that the same chemicals - acrylates - are used in many different types of gel and shellac nails.
  4. Eyelash Extensions: In the last few years, I've noticed an increase in the number of friends who use eyelash extensions ("fake eyelashes"). Adhesives are used to adhere to the skin of the eyelids. Some of these adhesives, such as cyanoacrylate, might cause allergic reactions in some people.4

Diagnosis and testing

The diagnosis of a shellac allergy typically involves a combination of medical history evaluation, clinical examination, and allergy testing. Here's an overview of the process:

Medical History: The healthcare provider will start by taking a detailed medical history, including questions about your symptoms, their duration and severity, and potential triggers or exposures to shellac-containing products. Be prepared to discuss your lifestyle and any occupational exposure to shellac.

Clinical Examination: A physical examination may be conducted to assess the extent and nature of any skin or mucous membrane reactions associated with shellac exposure.

Allergy testing:

Patch Testing: This is the most common method for diagnosing shellac allergy. Small amounts of shellac allergen are applied to patches, which are then placed on your skin (usually the back) for 48 hours. Your skin's reaction is assessed after this period.

Skin Prick Testing: In some cases, skin prick testing may be used to identify an immediate allergic reaction to shellac. A diluted extract of shellac is applied to your skin, and a tiny needle pricks the skin's surface. If you are allergic, you may develop a localized skin reaction within 15-20 minutes.

Blood Tests: Blood tests measuring specific IgE antibodies related to shellac allergy can also be performed. However, these are less commonly used than skin tests.

Elimination Diet: If a shellac allergy is suspected to be linked to food products, an elimination diet under the guidance of an allergist or immunologist may be recommended. This involves avoiding foods with shellac for a period and then reintroducing them to observe any allergic reactions.

Oral Challenge Test: In some cases, an oral challenge test may be conducted under medical supervision. Small amounts of shellac-containing food or medication are ingested to observe any allergic reactions.

Differential Diagnosis: It's important to rule out other potential causes of allergic reactions or skin conditions that may mimic shellac allergy. The healthcare provider will consider alternative diagnoses.

Once a diagnosis of shellac allergy is confirmed, your healthcare provider will work with you to develop a management and treatment plan. This typically involves avoiding shellac-containing products and, if necessary, prescribing medications to manage allergic symptoms. If you have a severe shellac allergy, carrying an epinephrine auto-injector (EpiPen) may be recommended for emergency use in case of anaphylaxis.1

Treatment and management

To begin, it is vital to ascertain whether the patient is allergic to this sort of nail coating. Despite the fact that the symptoms are very clear at first glance. It can take months of careful observation and testing to confirm a diagnosis. The doctor may prescribe the following medications to help the patient's condition:

  • Antihistamines – Stop the development of allergic symptoms such as itching, swelling, and skin redness. The treatment lasts between 1 and 1.5 weeks. Examples of drugs are Cetrizine, Levocetrizine, Ebastine, etc.
  • Corticosteroids and hormonal agents – eliminate itching, rash, swelling, and inflammation. These are local preparations – ointments Telekom and advantage. Treatment with them should be strictly under the supervision of a physician and not exceed ten days.
  • Burov’s liquid – Aids in the treatment of weeping skin inflammations.

A person suffering from allergies usually feels substantially better after a few days of such treatment. However, full recuperation is a time-consuming procedure. Its requirement is the termination of shellac use. Otherwise, subsequent allergic reactions will be even stronger.3

You can use the following recipes to repair nails that have been damaged by allergies:

  • Dip your hands in a solution of 1 tbsp sea salt in 500 ml of water for 10-15 minutes. Hands should be moistened with cream at the end of the procedure.
  • Lubrication of nails with iodine
  • Lubrication of nail plates with lemon juice for several minutes. The nails are cleaned with normal water after the treatment.
  • Apply currant, lingonberry, raspberry, or mountain ash puree to the nails for 15 minutes.5


In conclusion, shellac is a natural resin derived from the lac bug and finds applications in various industries such as woodworking, food production, cosmetics, and pharmaceuticals. While many individuals do not experience adverse reactions to shellac, it's important to recognize the significance of shellac allergies for those who may be sensitive. Shellac allergies can lead to a range of health and occupational concerns, including skin irritation, respiratory issues, and even anaphylaxis.

To address the importance of shellac allergies, it's crucial to:

  • Prioritize health and safety by promptly identifying and managing allergic reactions to shellac.
  • Educate individuals in occupations where shellac is commonly used about the risks and prevention measures.
  • Ensure accurate product labelling for allergen awareness, especially in the food, cosmetics, and pharmaceutical industries.
  • Mitigate the risk of cross-contamination in food production facilities to protect consumers.
  • Be aware of shellac's presence in medications and its potential impact on those with allergies.
  • Seek guidance from healthcare professionals, including allergists, for effective allergy management strategies.

Ultimately, understanding and addressing shellac allergies contribute to the well-being and safety of individuals in various settings and help prevent potentially serious allergic reactions.


  1. Shellac: Contact allergic dermatitis - DermNet [Internet]. Dermnetnz.org. [cited 2023 Sep 11]. Available from: https://dermnetnz.org/topics/contact-allergy-to-shellac
  2. Gov.in. [cited 2023 Sep 15]. Available from: https://www.fssai.gov.in/upload/uploadfiles/files/Compendium_Labelling_Display_23_09_2021.pdf
  3. Shellac Allergy - What is Shellac? Complete Guide – [Internet]. AllergiesInfo. 2022 [cited 2023 Sep 11]. Available from: https://allergiesinfo.com/allergies/shellac-allergy/
  4. Katta R. The Monday morning beauty hangover: allergic reactions to manicures, shellac nails, and hair dye [Internet]. doctorkatta. 2017 [cited 2023 Sep 14]. Available from: https://www.doctorkatta.com/post/2017/01/07/the-monday-morning-beauty-hangover-allergic-reactions-to-manicures-shellac-nails-and-hair
  5. Shellac Allergy - What is Shellac? Complete Guide – [Internet]. AllergiesInfo. 2022 [cited 2023 Sep 15]. Available from: https://allergiesinfo.com/allergies/shellac-allergy/
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Ann Rose Joseph

Doctor of Pharmacy - PharmD , Acharya and BM Reddy college of Pharmacy, Bangalore, Karnataka, India

Ann Rose is a PharmD intern , showcasing an unwavering passion for healthcare field. With comprehensive knowledge regarding the principles and operational techniques of pharmacy in Healthcare settings.Equipped with a strong background in medication evaluation and clinical management of multiple chronic disease states.

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