J AM ACAD DERMATOL

VOLUME 67, NUMBER 4Letters e143

REFERENCES

1. De Groot A, Conemans JMH. Systemic allergic contact derma-

titis from intravesical instillation of the antitumor antibiotic

mitomycin C. Contact Dermatitis 1991;24:201-9.

2. Kunkeler L, Nieboer C, Bruynzeel DP. Type III and type IV

hypersensitivity reactions due to mitomycin C. Contact Derma-

titis 2000;42:74-6.

3. Justiniano H, Berlingeri-Ramos AC, S�anchez JL. Pattern analysis

of drug-induced skin diseases. Am J Dermatopathol

2008;30:352-69.

4. Halevy S, Kardaun SH, Davidovici B, Wechsler J. The spectrum

of histopathological features in acute generalized exanthema-

tous pustulosis: a study of 102 cases. Br J Dermatol

2010;163:1245-52.

5. Corbal�an-V�elez R, Pe�on G, Ara M, Carapeto FJ. Localized toxic

follicular pustuloderma. Int J Dermatol 2000;39:209-11.

http://dx.doi.org/10.1016/j.jaad.2011.11.932

Fig 1. Chemical burn caused by topical acetic acid;clinical presentation and histologic features. A, Violaceousmacules and patches in left popliteal fossa along withscattered dome-shaped white papules. Largest patch isoriented in linear fashion in popliteal crease and hasirregular borders. There is a purple rim surroundingseveral white molluscum papules. B, Abrupt epidermalnecrosis with neutrophils within its lower portion andunderlying papillary dermis, along with fibrinoid vascularchanges just below epidermal necrosis. C, Portion ofepidermis is hyperplastic and displays intracytoplasmiceosinophilic inclusions (molluscum bodies) and acutenecrosis. (B and C, Hematoxylin-eosin stain; originalmagnifications: B, 320; C, 310.)

Chemical burn from topical apple cidervinegar

To the Editor: Chemical burns are often associatedwith strong acids such as sulfuric, nitric, and hydro-chloric acids, but can occur with weaker acids suchas acetic acid.1 An 8-year-old boy with a history ofCrohn’s disease and HLA-B27-positive spondy-loarthropathy had developed multiple lesions ofmollusca contagiosa on his left leg over severalweeks. His medications were weekly methotrexate(15 mg for the past year) and more recently, 3 dosesof adalimumab (40 mg every other week). Theevening before presentation, in an attempt to treatthe mollusca contagiosa, his mother applied cottonballs soaked in apple cider vinegar (;5% aceticacid) to the left popliteal fossa and side of his leftknee. Adhesive bandages were placed over thecotton balls and both were removed the nextmorning after approximately 8 hours of contacttime.

At the time of application, the patient noted aburning sensation, and the next day there were areasof violet discoloration and tenderness of the left leg.The patient also had developed a low-grade fever(102.28F). On physical examination, violaceous mac-ules and patches were seen with the largest lesionlocated in the popliteal crease; the latter was linearwith an irregular outline. A purple rim was notedaround the white papules of mollusca contagiosa(Fig 1, A). Given the history and that the mostprominent lesion was in the area of greatest occlu-sion, irritant contact dermatitis/chemical burn wasthe leading diagnosis. Because of the low-gradefever and the possibility of soft-tissue infection,however, two skin biopsies were performed, onefor routine histology and one for tissue culture.

Microscopic examination revealed abrupt epi-dermal necrosis with intraepidermal and papillary

dermal neutrophils; fibrinoid changes of papillarydermal vessels were visible beneath the areas ofepidermal necrosis (Fig 1, B and C ). Henderson-Paterson bodies were also present. Special stains,blood cultures, and tissue cultures all producednegative results.

Based on these findings, the patient was diag-nosed with a chemical burn caused by topical apple

Table I. Examples of sources of topical acetic acid

Type Strength of acetic acid (%) Possible ‘‘dermatologic’’ uses Potential side effects of topical application

Common vinegars Antiseptic; eradication of warts, lice,or mollusca; treatment of acnevulgaris

Chemical burn, including ulceration;scarring

Rice 4-5Apple cider 5Malt 5Balsamic 6Red/white wine 5-7Sherry 7-8

Glacial acetic acid 99.5-100 Chemical peels (self-administered) Chemical burn; hypertrophic scarring

J AM ACAD DERMATOL

OCTOBER 2012e144 Letters

cider vinegar. It is possible that there was lessabsorption of the acetic acid in the thickest portionof the mollusca contagiosa papules, leading to thepurple rims. The chemical burns healed withoutintervention. The mollusca did not respond to theacetic acid therapy but subsequently resolved withtopical cantharidin.

The US Food and Drug Administration man-dates that vinegars contain a minimum of 4%acetic acid; however, the concentrations of aceticacid found in commercially available vinegars canrange from 4% to 8%, depending on the exactsource of the vinegar (Table I). Chemical burnssecondary to topical application of vinegar havebeen rarely reported, but even ulceration has beenobserved.1-3 Of note, the undiluted form, glacialacetic acid, is available for purchase via theInternet and when applied, eg, as a self-administered facial chemical peel, has led to hy-pertrophic scarring.4 Given the increase in the useof alternative therapies for skin disorders, includ-ing the application of vinegar to warts, lice, andmollusca, chemical burns caused by acetic acidmay increase in incidence.

Christopher G. Bunick, MD, PhD,a Jason P. Lott, MD,a

Christine B. Warren, MD,a Anjela Galan, MD,a,b

Jean Bolognia, MD,a and Brett A. King, MD, PhDa

Departments of Dermatologya and Pathology,b YaleUniversity, New Haven, Connecticut

Funding sources: None.

Disclosure: Dr Bolognia receives royalties fromElsevier. Drs Bunick, Lott, Warren, Galan, andKing have no conflicts of interest to declare.

Correspondence to: Christopher G. Bunick, MD,PhD, 333 Cedar St, LCI 501, PO Box 208059,New Haven, CT 06520-8059

E-mail: christopher.bunick@yale.edu

REFERENCES

1. Korkmaz A, Sahiner U, Yurdakok M. Chemical burn caused by

topical vinegar application in a newborn infant. Pediatr

Dermatol 2000;17:34-6.

2. Kuniyuki S, Oonishi H. Chemical burn from acetic acid with

deep ulceration. Contact Dermatitis 1997;36:169.

3. Benmeir P, Lusthaus S, Weinberg A, Neuman A. Facial chemical

burn. Burns 1994;20:282.

4. Yoo JH, Roh SG, Lee NH, Yang KM, Moon JH. A case report of a

chemical burn due to the misuse of glacial acetic acid. J Plast

Reconstr Aesthet Surg 2000;63:e829-31.

http://dx.doi.org/10.1016/j.jaad.2011.11.934

Dermatoscopy of pigmented extramammaryPaget disease simulating melanoma

To the Editor: An 83-year-old man presented with avague 5- to 10-year history of an asymptomatic redrash in the left groin. On examination there was alarge plaque of erythema with depigmentation and asharp partly hyperpigmented margin. On the rightscrotum a large irregular hyperpigmented maculewas present (Fig 1, A).

Dermatoscopy of the pigmented lesion on thescrotum showed an irregular pattern with brown,blue-gray, and black globules sometimes linearlyarranged with a white background forming a whitenegative pigment network. A few dark-brown dotsand larger structureless brown and blue-gray areaswere seen (Fig 1, B). Vascular structures were notprominent. Although definite diagnostic criteria for amelanocytic lesion or pigmented Bowen diseasewere absent, neither of these diagnoses could beexcluded.

The histopathologic findings on the groin andscrotal lesions were similar, showing intraepidermalatypical cells arranged singly and in clusters. Inaddition the scrotal biopsy specimen showed abun-dant intracytoplasmic pigment in the atypical cellsand the presence of dermal melanophages (Fig 2, A).Immunohistochemistry demonstrated CK7 and CEA