Case report
Periungual furuncular myiasis: easily overlooked Lana Luiza Da Silva, MD, Christian D Cardozo Lomaquiz, MD, and Marcello Menta Simonsen Nico, MD
Department of Dermatology, Medical ~o Paulo, Sa ~o School, University of Sa Paulo, Brazil Correspondence Marcello Menta Simonsen Nico Department of Dermatology Medical School ~o Paulo University of Sa Rua Itapeva 500 3A ~o Paulo 01332-000 Sa Brazil E-mail: [email protected]
(a)
Case report A 60-year-old Brazilian woman presented with a severely painful lesion on the tip of the fourth right finger of four weeks’ duration. She had been treated with oral antibiotics for 15 days with no response. She did not recall any previous local trauma, and she was in good general health. Clinical examination showed a tender, erythematous, and diffuse enlargement of the distal phalanx of the right fourth finger, with some foci of superficial necrosis (Fig. 1a and b). Additionally, detailed inspection revealed a tiny and perfectly regular orifice on the center of the lesion, from which a serosanguinous fluid issued (Fig. 1c). No nail plate abnormalities were present. A diagnosis of furuncular cutaneous myiasis was established. After anesthetic blockade with lidocaine hydrochloride 2% at the base of the finger, a small amount of the anesthetic was injected underneath the nodule. This forced the tip of the worm to appear at the small orifice (Fig. 2a), when it was then gently and totally pulled with a forceps (Fig. 2b). The worm was identified as Dermatobia hominis, the human botfly. After two weeks, the lesion had totally cured.
(b)
(c)
Discussion Furuncular cutaneous myiasis is infestation by the larvae of several diverse genera of diptera: Cordylobia antropophaga (in Africa); Cuterera (in North America); and Dermatobia hominis (in Central and South America).1,2 Affected patients typically live or have recently traveled ª 2014 The International Society of Dermatology
Figure 1 (a) Dorsal view – periungueal swelling and erythema. (b) Lateral view – swelling and small foci of necrosis. At the center there is a 1-mm regular orifice. (c) Close up of (b). Detail of the draining orifice at the center of the lesion (arrow) International Journal of Dermatology 2015, 54, 817–818
817
818
Case report
Periungual furuncular myiasis
(a)
(b)
Figure 2 (a) The extremity of the larva is seen right after the
injection of anesthetic underneath the nodule. (b) The larva was then gently pulled by a forceps
to endemic areas; our patient lived in a rural area in the State of S~ao Paulo, Brazil, where the disease is occasionally observed. The botfly larva needs a warm-blooded animal to develop and, occasionally, emerges and becomes an adult fly. The biology of the botfly and its larval interaction with the skin of vertebrate animals has been extensively revised elsewhere.2–4 Furuncular myiasis characteristically causes a paroxysmal stinging sensation instead of continuous pain.4 This
International Journal of Dermatology 2015, 54, 817–818
Silva, Lamaquiz, and Nico
symptom allied with the finding of the typical discharging orifice surrounded by erythema and edema is diagnostic. This orifice represents the breathing tube of the larva.2,3 Treatment of furuncular myiasis is by removal of the larva. This is at times difficult to achieve; several treatment modalities have been described. A native treatment consists of occluding the orifice with pork fat, petrolatum, beeswax, or chewing gum in order to interfere with respiration of the larva, with consequent migration upward into the applied substance. Medical treatments include simple manual expression (which may kill and rupture the larva, with possible consequent cellulitis) or surgical extraction under local anesthesia.2–4 The pressure generated by the introduction of lidocaine hydrochloride, 1–2 ml underneath the nodule by using a syringe, pushes the larva out.5 This procedure was very effective in the present case; total removal of the larva was then obtained with a forceps. Our case is of interest as myiasis at this location is very rare and easily misdiagnosed; even local physicians, who should be familiar with myiasis, failed to correctly diagnose this particular presentation. Possible differential diagnoses here include bacterial or herpetic whitlow, gangrene, and even some tumors. The observation of the diagnostic clinical features with consequent larva removal helped to solve the puzzle. References 1 Szcurko C, Dompmartin A, Moreau A, et al. Ultrasonography of furuncular cutaneous myiasis: detection of Dermatobia hominis larvae and treatment. Int J Dermatol 1994; 33: 282–283. 2 Elgart EM. Flies and myiasis. Dermatol Clin 1990; 8: 237–244. 3 Gordon PM, Hepburn NC, Williams AE, et al. Cutaneous myiasis due to Dermatobia hominis: a report of six cases. Br J Dermatol 1995; 132: 811–814. 4 Robbins K, Khachemoune A. Cutaneous myiasis: a review of the common types of myiasis. Int J Dermatol 2010; 49: 1092–1098. 5 Nunzi E, Rongioleti F, Rebora A. Removal of Dermatobia hominis larvae. Arch Dermatol 1986; 122: 140.
ª 2014 The International Society of Dermatology
Periungual furuncular myiasis: easily overlooked Lana Luiza Da Silva, MD, Christian D Cardozo Lomaquiz, MD, and Marcello Menta Simonsen Nico, MD
Department of Dermatology, Medical ~o Paulo, Sa ~o School, University of Sa Paulo, Brazil Correspondence Marcello Menta Simonsen Nico Department of Dermatology Medical School ~o Paulo University of Sa Rua Itapeva 500 3A ~o Paulo 01332-000 Sa Brazil E-mail: [email protected]
(a)
Case report A 60-year-old Brazilian woman presented with a severely painful lesion on the tip of the fourth right finger of four weeks’ duration. She had been treated with oral antibiotics for 15 days with no response. She did not recall any previous local trauma, and she was in good general health. Clinical examination showed a tender, erythematous, and diffuse enlargement of the distal phalanx of the right fourth finger, with some foci of superficial necrosis (Fig. 1a and b). Additionally, detailed inspection revealed a tiny and perfectly regular orifice on the center of the lesion, from which a serosanguinous fluid issued (Fig. 1c). No nail plate abnormalities were present. A diagnosis of furuncular cutaneous myiasis was established. After anesthetic blockade with lidocaine hydrochloride 2% at the base of the finger, a small amount of the anesthetic was injected underneath the nodule. This forced the tip of the worm to appear at the small orifice (Fig. 2a), when it was then gently and totally pulled with a forceps (Fig. 2b). The worm was identified as Dermatobia hominis, the human botfly. After two weeks, the lesion had totally cured.
(b)
(c)
Discussion Furuncular cutaneous myiasis is infestation by the larvae of several diverse genera of diptera: Cordylobia antropophaga (in Africa); Cuterera (in North America); and Dermatobia hominis (in Central and South America).1,2 Affected patients typically live or have recently traveled ª 2014 The International Society of Dermatology
Figure 1 (a) Dorsal view – periungueal swelling and erythema. (b) Lateral view – swelling and small foci of necrosis. At the center there is a 1-mm regular orifice. (c) Close up of (b). Detail of the draining orifice at the center of the lesion (arrow) International Journal of Dermatology 2015, 54, 817–818
817
818
Case report
Periungual furuncular myiasis
(a)
(b)
Figure 2 (a) The extremity of the larva is seen right after the
injection of anesthetic underneath the nodule. (b) The larva was then gently pulled by a forceps
to endemic areas; our patient lived in a rural area in the State of S~ao Paulo, Brazil, where the disease is occasionally observed. The botfly larva needs a warm-blooded animal to develop and, occasionally, emerges and becomes an adult fly. The biology of the botfly and its larval interaction with the skin of vertebrate animals has been extensively revised elsewhere.2–4 Furuncular myiasis characteristically causes a paroxysmal stinging sensation instead of continuous pain.4 This
International Journal of Dermatology 2015, 54, 817–818
Silva, Lamaquiz, and Nico
symptom allied with the finding of the typical discharging orifice surrounded by erythema and edema is diagnostic. This orifice represents the breathing tube of the larva.2,3 Treatment of furuncular myiasis is by removal of the larva. This is at times difficult to achieve; several treatment modalities have been described. A native treatment consists of occluding the orifice with pork fat, petrolatum, beeswax, or chewing gum in order to interfere with respiration of the larva, with consequent migration upward into the applied substance. Medical treatments include simple manual expression (which may kill and rupture the larva, with possible consequent cellulitis) or surgical extraction under local anesthesia.2–4 The pressure generated by the introduction of lidocaine hydrochloride, 1–2 ml underneath the nodule by using a syringe, pushes the larva out.5 This procedure was very effective in the present case; total removal of the larva was then obtained with a forceps. Our case is of interest as myiasis at this location is very rare and easily misdiagnosed; even local physicians, who should be familiar with myiasis, failed to correctly diagnose this particular presentation. Possible differential diagnoses here include bacterial or herpetic whitlow, gangrene, and even some tumors. The observation of the diagnostic clinical features with consequent larva removal helped to solve the puzzle. References 1 Szcurko C, Dompmartin A, Moreau A, et al. Ultrasonography of furuncular cutaneous myiasis: detection of Dermatobia hominis larvae and treatment. Int J Dermatol 1994; 33: 282–283. 2 Elgart EM. Flies and myiasis. Dermatol Clin 1990; 8: 237–244. 3 Gordon PM, Hepburn NC, Williams AE, et al. Cutaneous myiasis due to Dermatobia hominis: a report of six cases. Br J Dermatol 1995; 132: 811–814. 4 Robbins K, Khachemoune A. Cutaneous myiasis: a review of the common types of myiasis. Int J Dermatol 2010; 49: 1092–1098. 5 Nunzi E, Rongioleti F, Rebora A. Removal of Dermatobia hominis larvae. Arch Dermatol 1986; 122: 140.
ª 2014 The International Society of Dermatology
