Iatrogenic allergic contact dermatitis in the (peri)anal and genital area

Perianal Ulcers from Antihemorrhoidal Ointment: A Case Report and Literature Review

ABSTRACT

Perianal ulcers (PAUs) related to antihemorrhoidal product use have been recently reported in the literature through a few case reports. However, other etiologies of PAU must be ruled out, including infectious disease, inflammatory disease, malignancy, pressure injuries, radiotherapy, and other topical drugs. In this report, the authors describe two cases of PAUs due to an antihemorrhoidal ointment. In case 1, a 68-year-old woman with a history of hemorrhoids presented with PAUs after using an antihemorrhoidal ointment for 2 months. The ulcers were assessed through a histopathologic study and treated with calcium alginate dressings, with complete re-epithelialization occurring after 2 months. In case 2, a 58-year-old woman with a history of hemorrhoids developed painful PAUs while using an antihemorrhoidal ointment for 2 months. No other probable cause was found, and the ulcers were treated by discontinuing the ointment. The ulcers showed marked improvement, and complete re-epithelialization occurred after 6 weeks without additional treatment.

Allergic contact dermatitis from propylene glycol: A case series from Australia

BACKGROUND

Propylene glycol (PG) is used in a variety of cosmetics, food and pharmaceuticals. PG is a known sensitizer but also irritating when patch tested (PT).

OBJECTIVES

The aims were to investigate the frequency of contact sensitization to PG and to identify cases of allergic contact dermatitis (ACD).

METHODS

A retrospective study was performed on patients PT at the Skin Health Institute (SHI), Victoria, Australia to PG 5% pet. and PG 10% aq. between 1 January 2005 and 31 December 2020.

RESULTS

In all, 6761 patients were PT to PG and 21 (0.31%) reacted. Of those 21 individuals, 9 (42.9%) had a relevant reaction. 75% of relevant positive reactions were in patients PT to PG 10% aq. The most common source of PG exposure was topical medicaments (77.8% of relevant reactions) and moisturizers, with the largest group being topical corticosteroids.

CONCLUSION

Contact sensitization to PG in the patch test population remains uncommon, although it is possible that testing with concentrations of 5%-10% PG did not identify all reactions. Topical corticosteroids were the most important cause. Patients with suspected contact dermatitis to topical corticosteroids should be PT to PG.

A systematic review of allergic and irritant contact dermatitis of the vulva: The most important allergens/irritants and the role of patch testing

Vulvar allergic contact dermatitis (vACD) and irritant contact dermatitis (vICD) are common and accompanied by a great burden on the patient's life. We aimed to review the existing literature on vACD and vICD in order to provide a comprehensive reference list of potential vulvar allergens and irritants, as well as to establish the role of patch testing therein. A systematic search was performed in Medline, Embase and Web of Science using a search string based on the PICO-format. The study protocol was registered at PROSPERO (CRD42021239527). Multiple allergens were identified and included metals, topical drugs, fragrances, preservatives, cosmetic constituents and rubber components. Not all positive reactions were, however, considered to be relevant. Patch testing is the primary tool for the identification of the causal allergens. Testing with standard series alone was proven to be insufficient. Little information about irritants was found. In the future, additional series and late readings should be considered in standard practice. Studies on vICD are scarce and further research is necessary. More population-based research should be performed.

Lanolin

Lanolin is a complex mixture of high molecular weight esters, aliphatic alcohols, sterols, fatty acids, and hydrocarbons that has been widely used for centuries for its emollient properties. The purification of crude lanolin into lanolin wax and the processing of this wax into various derivatives began in 1882 and continue to this day with newer highly purified anhydrous lanolins. Controversy as to lanolin's allergenicity began in the 1920s and remains an issue. The most appropriate patch test preparation(s) for detecting allergy remain disputed. Detection of lanolin-induced contact dermatitis in diseased skin by patch testing on normal skin may lead to false negative results. Patients with a positive patch test to lanolin may tolerate use of lanolin on normal skin. Although lanolin is a weak sensitizer and the frequency of contact allergy to it in the European population reportedly is 0.4%, there are high-risk concomitant conditions: stasis dermatitis, leg ulcers, perianal/genital dermatitis, and atopic dermatitis (AD). Children and the elderly are also at greater risk of developing contact allergy to lanolin, partly because of comorbidities (AD and stasis dermatitis/leg ulcers, respectively). Finally, in the United States, non-Hispanic white patients are more likely than their non-Hispanic black counterparts to be lanolin allergic.

Contact Dermatitis of the Vulva

The vulvar area is a common site of both irritative and allergic contact dermatitis due to the thin skin, easily traversable by irritant and allergic substances. The purpose of this review is to provide an overview of the most frequent allergens causing contact dermatitis in this particular site. A literature search was conducted via PubMed through May 2021. Relevant English language studies are included in this review. Fragrances, preservatives, botanical products, and topical medicaments were found to be the most commonly involved allergens. Contact dermatitis is a very common occurrence that should also be considered in patients with chronic vulvar or anogenital dermatitis who do not respond to appropriate treatments.