Malignant intertrigo
====================

* Connie Liu
* Mei-Ju Ko

A 55-year-old woman was referred to the dermatology department for an intertriginous eruption of one week’s duration. She had undergone breast-conserving surgery for stage 2 breast cancer. Two weeks before the start of the eruption, she had been started on a chemotherapy regimen with cyclophosphamide and doxorubicin.

On physical examination, the patient had multiple painful erythematous to dull-red patches with crusting and erosions over the intertriginous areas including the axillae and groin (Figure 1A). Scattered bullae were also found in the axillary region (Figure 1B). Skin cultures were taken to test for the presence of bacteria and fungi; results for these tests were negative.

![Figure 1:](http://www.cmaj.ca/https://www.cmaj.ca/content/cmaj/190/19/E595/F1.medium.gif)

[Figure 1:](http://www.cmaj.ca/content/190/19/E595/F1)

Figure 1: 
(A) Painful skin eruptions over the intertriginous areas that developed two weeks after chemotherapy for breast cancer in a 55-year-old woman. (B) Multiple erythematous to dull-red patches with erosion and scattered bullae in the axillary region.

A biopsy of the right axilla showed subepidermal and supra-basal vesicular dermatitis with epidermal necrosis and mixed infiltration of neutrophils and eosinophils. These findings were consistent with malignant intertrigo, the intertriginous pattern of toxic erythema caused by chemotherapy. The eruption responded well to prednisolone administered orally (5 mg twice daily), along with topical betamethasone and zinc oxide suspension (twice daily).

Malignant intertrigo often presents with erythematous patches with scales, crusts and erosions over intertriginous regions that usually develops two days to three weeks after the administration of chemotherapeutic agents.1 Its pathophysiology is presumed to be caused by local accumulation of cytotoxic chemicals. At present, cytarabine and pegylated liposomal doxorubicin are the most frequently reported causative agents.1,2 This condition is usually a self-limiting eruption; however, recurrence with readministration of the offending agent is not uncommon.1,2

Usually, malignant intertrigo is not reported, and the incidence may be higher than expected. Diagnosis is based mainly on typical clinical presentation.1,2 Negative results for bacterial and fungal cultures, and no satellite lesions at the periphery distinguish malignant intertrigo from infectious intertrigo. Intertriginous distribution discriminates malignant intertrigo from other chemotherapy-related skin eruptions. Early recognition of this entity, and management with topical or oral corticosteroids and general topical measures can provide palliation of symptoms, and prevent unnecessary and potentially harmful treatments.1,3

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## Footnotes

*   **Competing interests:** None declared.

*   This article has been peer reviewed.

*   The authors have obtained patient consent.

## References

1.  Smith SM, Milam P, Fabbro S, et al. Malignant intertrigo: a subset of toxic erythema of chemotherapy requiring recognition. JAAD Case Rep 2016;2:476–81.
    
    

2.  Martorell-Calatayud A, Sanmartín O, Botella-Estrada R, et al. Chemotherapy-related bilateral dermatitis associated with eccrine squamous syringometaplasia: reappraisal of epidemiological, clinical, and pathological features. J Am Acad Dermatol 2011;64:1092–103.
    
    [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1016/j.jaad.2010.04.021&link_type=DOI) 
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=21489654&link_type=MED&atom=%2Fcmaj%2F190%2F19%2FE595.atom) 

3.  Carvalho R, Macias V, Marques-Pinto G, et al. Intertriginous pattern of toxic erythema of chemotherapy. Cutan Ocul Toxicol 2011;30:309–11.
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=21501039&link_type=MED&atom=%2Fcmaj%2F190%2F19%2FE595.atom)