ARTICLE Inflammatory Tinea Pedis/Manuum Masquerading as Bacterial Cellulitis Susan M. Sweeney, MD; Karen Wiss, MD; Susan Bayliss Mallory, MD Background: Tinea pedis and tinea manuum in chil- performed on 3 patients. Fungal cultures were per- dren are more common than previously recognized. Clini- formed on 2 patients. cal presentations of dermatophyte infections may vary in children and may be difficult to diagnose. Results: Inflammatory/bullous dermatophyte infec- tions were detected by potassium hydroxide examina- Objective: To show the necessity of potassium hydrox- tion in all 4 patients and all 4 children successfully re- ide preparations and/or fungal cultures in assessing sus- sponded to topical antifungal therapy. picious cases of cellulitis in children who may have der- matophyte infections. Conclusions: These cases demonstrate that inflamma- tory tinnea pedis/manuum can masquerade as cellulitis Patients: We describe 4 children with inflammatory tinea in children. Early potassium hydroxide examination can pedis or tinea manuum who were initially misdiag- allow appropriate antifungal treatment to be initiated be- nosed as having bacterial cellulitis. fore fungal culture results are finalized. Intervention: A potassium hydroxide examination was Arch Pediatr Adolesc Med. 2002;156:1149-1152 INEA PEDIS and tinea thema and edema on the right plantar foot. He manuum were thought to was treated with oral amoxicillin–clavulanic acid be rare cutaneous infec- for presumed mild cellulitis. After 3 days of tak- tions in prepubertal chil- ing oral antibiotics, there was no improve- dren.1,2 More recent re- ment. A pediatric surgeon performed incision and drainage of the lesion but the blister ports in the dermatologic literature suggest T promptly recurred. Three days later, the pa- that dermatophyte infections of the feet tient was seen in the emergency department of and hands are more common in children Children’s Hospital (Boston, Mass). He was di- 3,4 than previously recognized. The clini- agnosed as having refractory bacterial cellulitis cal presentation of superficial fungal in- and scheduled for hospital admission for intra- fections in children may be varied, non- venous antibiotics. A bacterial culture was per- specific, and somewhat confusing.5 formed and complete blood cell count re- We describe 4 children with tinea pe- vealed no evidence of eosinophilia. Just prior to dis or tinea manuum who were initially his hospitalization, he was referred to the der- misdiagnosed as having bullous impe- matology clinic, where a physical examination tigo with bacterial cellulitis. The correct revealed an afebrile young boy with a 2-cm bulla diagnosis was made after a potassium hy- surrounded by erythema and microvesicles on the right plantar foot (Figure 1 and Figure 2). droxide (KOH) examination was per- A KOH examination was performed. formed. These patients are described to en- courage pediatricians to perform KOH PATIENT 2 From the Departments of preparations and/or fungal cultures in sus- Medicine (Drs Sweeney and picious cases of cellulitis in children. An 8-year-old white female was seen in the der- Wiss) and Pediatrics (Dr Wiss), matology clinic at St Louis Children’s Hospi- Division of Dermatology, tal (St Louis, Mo) with a 12-month history of University of Massachusetts METHODS a 1- to 2-cm recurrent lesion on her foot. Ac- Medical School, Worcester; and cording to her parents, the lesion appeared as the Department of Pediatrics, PATIENT 1 a blister, became swollen and tender, and then Washington University School resolved spontaneously, with episodes occur- of Medicine, St Louis Children’s A 6-year-old white male visited his pediatri- ring approximately every month. The family Hospital, St Louis, Mo cian with a 1-day history of a painful and pru- history revealed recurrent bouts of herpes la- (Dr Mallory). ritic enlarging blister with surrounding ery- bialis in both parents and a tinea pedis infec- (REPRINTED) ARCH PEDIATR ADOLESC MED/ VOL 156, NOV 2002 WWW.ARCHPEDIATRICS.COM 1149 ©2002 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 10/01/2021 Figure 1. Bulla with surrounding erythema on the right plantar foot. Figure 4. Vesicles and bullae on the thenar eminence of the left hand. Figure 2. Closer view of bulla seen in Figure 1 with surrounding Figure 5. Annular collection of vesicles with surrounding erythema on the microvesicles. right plantar foot. by lymphangitic streaking. Individual blisters healed but new ones promptly formed in the same areas. Outpatient treat- ment with oral erythromycin, oral cephalexin, topical poly- mixin B sulfate/Bacitracin zinc ointment, and topical mupiro- cin for presumed bullous impetigo with cellulitis and lymphangitis resulted in minimal improvement. On physical examination, the girl was afebrile and had a 4-cm collection of vesicles and bullae with crusting on the thenar eminence (Figure 4). Surrounding erythema extended onto the fore- arm. There was no evidence of tinea pedis. Viral, bacterial, and fungal cultures were performed. PATIENT 4 A 10-year-old white female was hospitalized at St Louis Chil- dren’s Hospital for presumed bacterial or herpetic cellulitis on Figure 3. Bulla with surrounding erythema and edema on the left lateral foot. the plantar surface of the right foot. She was treated with in- travenous antibiotics and intravenous acyclovir for 1 week, with minimal improvement. Dermatology consultation was ob- tion in the patient’s father. On physical examination, a 1.5-cm tained. A physical examination demonstrated a 3-cm annular bulla with surrounding erythema and edema was present on collection of vesicles with surrounding erythema (Figure 5). the left lateral foot (Figure 3). The differential diagnoses in- A KOH examination was performed. cluded herpes simplex infection, inflammatory tinea pedis, and bullous impetigo with cellulitis. A KOH examination and fun- gal and viral cultures were performed. RESULTS PATIENT 3 PATIENT 1 A 6-year-old white female was brought to the dermatology clinic The KOH preparation revealed multiple branched hy- at St Louis Children’s Hospital with a several-week history of phae. A fungal culture was not obtained. He was diag- blisters on her left palm. The blisters appeared first, followed nosed as having inflammatory/bullous tinea pedis and (REPRINTED) ARCH PEDIATR ADOLESC MED/ VOL 156, NOV 2002 WWW.ARCHPEDIATRICS.COM 1150 ©2002 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 10/01/2021 treated with 1% naftifine hydrochloride cream twice daily What This Study Adds on an outpatient basis, with improvement of symptoms within 3 days. Review of histopathologic studies of a skin sample obtained during the incision and drainage pro- Inflammatory tinea pedis/manuum can be difficult to di- agnose in children, as it may mimic several other skin cedure revealed vesiculopustular dermatitis with hy- conditions, including cellulitis. Pediatricians who con- phal elements in the stratum corneum, consistent with sider fungal infection as a possible cause of vesicles and tinea pedis. bullae are more likely to perform a KOH examination or fungal culture. In this manner, children with inflam- PATIENT 2 matory tinea pedis/manuum can receive antifungal treat- ment early in the course of the disease, thus expediting The viral culture was negative. Hyphae were revealed by the recovery process. KOH preparation and the fungal culture demonstrated Trichophyton rubrum. The patient was treated with 2% mi- conazole nitrate cream twice daily, with prompt resolution. tinea pedis or tinea manuum that were mistaken for bac- terial or herpetic cellulitis. In the first case, a young boy PATIENT 3 underwent a surgical procedure and was almost hospi- talized for parenteral antibiotic treatment of refractory The viral and bacterial cultures were negative for organ- cellulitis before the correct diagnosis was discovered. Simi- isms. A fungal culture grew T rubrum. She was treated larly, patient 4 was treated unsuccessfully with a week with 1% terbinafine hydrochloride cream twice daily, with of parenteral antibiotics (including acyclovir) before a complete resolution. The patient is a gymnast and fre- KOH preparation was performed. quently works out using the parallel bars, possibly ex- The KOH preparation is simple, inexpensive, effi- posing her to dermatophytes. cient, and widely available to all physicians. By gently scrap- ing the infected skin or blister roof with a sterile scalpel PATIENT 4 blade, a KOH mount can be easily prepared on a glass slide with 1 to 2 drops of 10% KOH. The sample is then exam- The KOH preparation revealed multiple hyphae. A fun- ined under the microscope for the presence of hyphae. Al- gal culture was not obtained. The patient was diagnosed though an inexperienced physician may have some diffi- as having inflammatory/bullous tinea pedis. All antibi- culty identifying hyphae, most clinical laboratories can otics were discontinued. She was treated with 1% terbi- perform a standard KOH preparation or calcofluor white nafine hydrochloride cream twice daily, with complete on scrapings sent in a sterile container. T rubrum, Tricho- resolution. phyton mentagrophytes, and, less commonly, Epidermophy- ton floccosum are the most common dermatophytes iso- 9 COMMENT lated in tinea pedis. Superficial dermatophyte infections of the skin typi- Tinea pedis may be more common in young children than cally respond well to a variety of topical antifungal agents, previously believed.3,5 Recent reports stress the impor- including clotrimazole, econazole, oxiconazole, micona- tance of performing KOH examinations and fungal cul- zole, terbinafine, and naftifine applied to the affected areas tures in pediatric patients with foot dermatitis.6,7 Kearse twice daily for 2 to 4 weeks.10,11 The duration of treat- and Miller3 described 15 children (2-13 years old) with ment may be ultimately determined by continuing topi- presumed foot dermatitis; 8 of those patients were found cal application for 1 week after the clinical signs and symp- to have dermatophyte infections, identified with KOH toms have completely resolved.10 Adjunctive measures to preparations.