Answer: B

Irritant contact dermatitis (ICD) is a localized inflammatory skin reaction to physical or chemical agents. It is the most common form of contact dermatitis and is distributed on the hands more frequently than allergic contact dermatitis.10,11 Infants are the most sensitive to skin irritants and therefore prone to developing ICD.12 In the adult population, individuals involved in “wet work” are at high risk for occupational ICD.13 “Wet work” is defined as washing hands, wearing gloves, or touching water for more than 2 hours per day. 10 This commonly includes workers in health care, mechanics, cleaning, or food industries. 13 ICD commonly affects women more than men, likely due to increased domestic and occupational exposures.11

The pathophysiologic mechanism of ICD is dependent upon innate immune system activation. As such, ICD can develop with the first exposure to a skin irritant, unlike ACD, which requires initial sensitization.3 The first step in acute ICD development is damage to the epidermal skin barrier, resulting in cytokine release and leukocyte recruitment.14 Exposure to water causes the stratum corneum to swell and the skin lipids to separate.15 Detergents and alkaline substances also damage hydrophobic lipids in the skin via saponification, and acids act by denaturing proteins. Physical irritants such as fiberglass and wood break the skin through repetitive trauma. Environmental factors also play a role in ICD pathogenesis. In high heat and humidity, the skin barrier is more susceptible to irritant entry. However, cold temperatures also contribute to ICD because increased water loss compromises the skin barrier.16 The pathogenesis of chronic ICD is more poorly understood, but the long-term exposure to an irritant is believed to down-regulate immune responses and induce skin proliferation.17 The acanthosis and hyperkeratosis that result are known as a “hardening phenomenon.”18

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The clinical presentation of ICD is highly variable depending on irritant strength and skin sensitivity. The mildest form involves skin dryness and erythema, and the most severe presentation includes skin necrosis. In acute ICD, patients often complain of a stinging or burning pain. It is characterized by vesicles, edema, erythema, and scaling. Corrosive chemicals can elicit ulcers and necrosis. Chronic ICD presents with dry, fissured skin, hyperkeratosis, and a glazed appearance.19 In both acute and chronic ICD, the rash is sharply circumscribed and defined by the area of contact.8 Histologically, acute ICD shows spongiosis, epidermal bullae or vesicles, edema, and keratinocyte necrosis. Microscopically, chronic ICD has hyperkeratosis, parakeratosis, acanthosis, and hypergranulosis.20 Of note, histopathology cannot be used to distinguish ACD and ICD.21

The differential diagnosis of ICD includes ACD, eczema, psoriasis, tinea, and scabies. Scabies frequently affects the hands but usually presents with intense pruritus, which is less common in ICD. Psoriasis and chronic ICD can appear very similar on physical examination, but the characteristic presence of nail changes or plaques on the elbows and knees points toward psoriasis.

Diagnosing ICD depends mostly on detecting localized dermatitis on physical examination, which is supported by an in-depth history revealing exposure to an irritant. Given the similar appearance and histology of ACD, ruling out ACD with the use of patch testing is commonly performed.19 Although CD and ACD can coexist, this is rare and happens most frequently in occupations involving wet work.22 When there is concern for other skin pathologies, skin biopsy can be useful, and a potassium hydroxide prep can rule out fungal infection.

The most critical component of ICD treatment is irritant avoidance. For those with work exposures, using plastic instead of rubber gloves and adding cotton liners under gloves can aid in sweat absorption. In addition, thoroughly drying hands after washing can reduce the damaging effects of water on the skin barrier. Additional therapy includes topical corticosteroids to reduce inflammation, as well as emollients, moisturizers, or barrier creams. These creams restore the skin barrier and should be applied multiple times a day for optimal efficacy.5 At our patient’s next visit, he brought the gas mask he was required to wear.  It was noted that the mask was coming in contact with his face in the areas of irritant contact dermatitis.  On further questioning, the patient noted that he was cleaning his gas mask daily with harsh chemicals (required to potentially remove toxic gas residue).  The patient was advised to wash off the mask a second time in order to remove the harsh cleaning chemicals used during cleaning.  This led to resolution of his ICD.

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Jessica C. Sheu, BA, and Michelle E. Lee, BA, are medical students at Baylor College of Medicine in Houston, Texas. Christopher Rizk, MD, is a dermatologist with Elite Dermatology in Houston, Texas.


1. Becker D. Allergic contact dermatitis. J Dtsch Dermatol Ges. 2013;11(7):607-619.

2. Saint-Mezard P, Rosieres A, Krasteva M, et al. Allergic contact dermatitis. Eur J Dermatol. 2004;14(5):284-295.

3. Kostner L, Anzengruber F, Guillod C, Recher M, Schmid-Grendelmeier P, Navarini AA. Allergic contact dermatitis. Immunol Allergy Clin North Am. 2017;37(1):141-152.

4. Nelson JL, Mowad CM. Allergic contact dermatitis: patch testing beyond the TRUE test. J Clin Aesthet Dermatol. 2010;3(10):36-41.

5. Usatine RP, Riojas M. Diagnosis and management of contact dermatitis. Am Fam Physician. 2010;82(3):249-255.

6. Sharma VK, Asati DP. Pediatric contact dermatitis. Indian J Dermatol Venereol Leprol. 2010;76(5):514-520.

7. So JK, Hamstra A, Calame A, Hamann CR, Jacob SE.  Another great imitator: allergic contact dermatitis differential diagnosis, clues to diagnosis, histopathology, and treatment. Curr Treat Options Allergy. 2015;2(4):333-348.

8. Beltrani VS, Bernstein IL, Cohen DE, Fonacier L. Contact dermatitis: a practice parameter. Ann Allergy Asthma Immunol. 2006;97(3 Suppl 2):S1-38.

9. Belsito D, Wilson DC, Warshaw E, et al. A prospective randomized clinical trial of 0.1% tacrolimus ointment in a model of chronic allergic contact dermatitis. J Am Acad Dermatol. 2006;55(1):40-46.

10. Clark SC, Zirwas MJ. Management of occupational dermatitis. Dermatol Clin. 2009;27(3):365-383.

11. Thyssen JP, Johansen JD, Linneberg A, Menné T. The epidemiology of hand eczema in the general population — prevalence and main findings. Contact Dermatitis. 2010;62(2):75-87.

13. Dickel H, Kuss O, Schmidt A, Kretz J, Diepgen TL. Importance of irritant contact dermatitis in occupational skin disease. Am J Clin Dermatol. 2002;3(4):283-289.

12. Schwindt DA, Wilhelm K-P, Miller DL, Maibach HI. Cumulative irritation in older and younger skin: a comparison. Acta Derm Venereol. 1998;78(4):279-283.

14. Angelova-Fischer I, Stilla T, Kezic S, Fischer TW, Zillikens D.  Barrier function and natural moisturizing factor levels after cumulative exposure to short-chain aliphatic alcohols and detergents: results of occlusion-modified tandem repeated irritation test. Acta Derm Venereol. 2016;96(7):880-884.

15. Spears MJ, McKillop K, Marshall JL, et al. Water disrupts stratum corneum lipid lamellae: damage is similar to surfactants. J Invest Dermatol. 1999;113(6):960-966.

16. Zhai H, Maibach HI. Skin occlusion and irritant and allergic contact dermatitis: an overview. Contact Dermatitis. 2001;44(4):201-206.

17. Visscher MO, Said D, Wickett R. Stratum corneum cytokines, structural proteins, and transepidermal water loss: effect of hand hygiene. Skin Res Technol. 2010;16(2):229-236.

18. Watkins SA, Maibach HI. The hardening phenomenon in irritant contact dermatitis: an interpretative update. Contact Dermatitis. 2009;60(3):123-130.

19. Ale IS, Maibach HI. Irritant contact dermatitis. Rev Environ Health. 2014;29(3):195-206.

20. Willis CM, Stephens CJM, Wilkinson JD. Epidermal damage induced by irritants in man: a light and electron microscopic study. J Invest Dermatol. 1989;93(5):695-699.

21. Frings VG, Böer-Auer A, Breuer K. Histomorphology and immunophenotype of eczematous skin lesions revisited — skin biopsies are not reliable in differentiating allergic contact dermatitis, irritant contact dermatitis, and atopic dermatitis. Am J Dermatopathol 2018;40(1):7-16.

22. Schwensen JF, Menné T, Johansen JD. The combined diagnosis of allergic and irritant contact dermatitis in a retrospective cohort of 1000 consecutive patients with occupational contact dermatitis. Contact Dermatitis. 2014;71(6):356-363.