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Localized scalp hair shedding by pheidole ant and overwiew of similar case reports

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Localized scalp hair shedding caused by Pheidole ants and overwiew of similar case reports
S Shamsadini
Dermatology Online Journal 9(3): 12

From the Kerman University of Medical Sciences, Kerman Iran.


Localized hair shedding caused by Pheidole ants is reported as a newly recognized type of hair loss, mimicking alopecia areata. We report two cases from Kerman, Iran. This sudden hair loss demonstrates that ants such as the Pheidole dimorphic species can cause hair shedding. Fairly clean cutting of the scalp hair takes place just a few micrometers above the skin surface and simulates alopecia areata or mechanical shaving of scalp hair. This infestation has not been reported from other countries, and this report is the second from Iran.


Scalp hair cutting or breakage by Pheidole ants just above the scalp surface can simulate close shaving or alopecia areata and has only recently been described by Radmanesh and Mousavipour in Iran. [1, 2, 3] The Pheidole species are believed to be lipophilic and therefore may be attracted to relatively greasy scalps.[4] From May 12, 1998, to January 18, 1999, a total of 16 cases were referred to the dermatology center of Ahwas University from two different cities in that province. [1] We present two additional cases with sudden scalp hair shedding associated with Pheidole ant infestation. Sudden localized hair shedding in round or oval shapes was the first presenting sign of parasitic infestation by these ants. Other causes of sudden hair shedding such as alopecia areata and trichotillomania must be ruled out in this disease. [1, 4]

Report of cases

Figure 1Figure 2
Mild erythema and signs of scratching with hair loss mimicking alopecia areata. The Pheidole ant species, red-brown in color and believed to be a lipophilic parasite.

Case 1.—An 18-year-old male student noted sudden onset of localized scalp hair loss overnight. His parents found clumps of hair on his pillow. Some dead brown-red ants were seen inside the hair clumps. On physical examination, there was a 3.5cm by 3.5 cm patch of alopecia on the right side of the vertex scalp that also showed mild erythema. The patient also complained of mild pruritus at the site. All the hair had been cut just above the scalp skin surface (Fig 1). The ants were 3-4 mm long and 0.5-1 mm wide (Fig 2). The clinical picture and the presence of ants within the shed hair clumps pointed to the diagnosis of Pheidole ant infestation. There were no clinical signs of any other parasitic infestation such as pediculosis or scabies in this patient and the rest of his skin exam was normal. Oral antihistamine therapy was begun for mild pruritus.

Case 2.—A 31-year-old woman was referred to the dermatology center in the province of Kerman. Her chief complaint was sudden localized hair shedding at night during sleep. She described noticing the hair loss and finding some brown ants among shed hairs. Signs of other known parasitic infestations such as pediculosis and scabies were not observed. Therapy with diphenhydramine (Calamin®) lotion was begun to her scalp.


Hair shedding simulating alopecia areata by Pheidole ants was not well established in humans previously. The disease was first described in 1999 [1, 2]. We report two cases of Pheidole ant infestation with scalp hair shedding in a young man and in an adult woman from Kerman, a province of Iran. Hair cutting is accomplished by the powerful jaws of this big-headed ant, although it is unclear whether some dissolving substance is also used. [1, 2, 3, 4, 5] The reason for this attack on the hair is unknown. Hairs may be used by the ants for nutritional, nest-building, or other purposes.

Pheidole species consists of big-headed ants with two nodal spines on the thorax. [2, 5, 6] The ants are dimorphic, meaning they have two sizes in a colony. [3, 4, 5] The smaller size, or minor worker, gathers seeds; the larger, or major worker, uses its oversized head and jaws to break the seeds open. [1, 2, 5, 7]. Big-headed ants usually have small colonies, but they can have several colonies around or in a structure. [1,3] These ants are grain and seed feeders. They are often found feeding on cakes, breads, and pet food products. [2, 4] They enter homes through expansion joints or cracks in the slab. [2, 3, 5] Protein-containing baits are generally effective against these ants. Granular baits can be applied to the nests outside if they are found. [3,6]

A total of 18 cases of Pheidole ant hair shedding have been reported from the dermatology clinics of Ahwas and Kerman (two separated provinces of Iran). The type of hair shedding in all of them was similar with sudden onset and localized distribution on their scalps. Our two cases were from Kerman. Three cases have been reported from Ahwaz, and 13 cases have been from Behbahan, a city 200 kilometers away from Ahwaz. All 18 reported cases have been from Iran, and there were 14 males versus 4 females. Many parasites were seen among shed hair masses on the pillows and bed linens of these patients after awakening. The diagnosis may be suggested after ruling out other diagnoses such as alopecia areata or trichotillomania. [1]

In an area endemic for Pheidole ants, the detection of overnight shedding of clumps of hair with or without finding the parasites should stimulate a consideration of this infestation.


1. Radmanesh M, Mousavipour M. Alopecia induced by ants. Trans R Soc Trop Med Hyg. 1999 Jul-Aug;93(4):427. PubMed

2. Brown WL Jr. Preliminary contribution toward a revision of the ant genus Pheidole (Hymenoptera: Formicidae). Part 1. Journal of the Kansas Entomological Society, 1981. 54:523-530.

3. Ogata,K.A. A generic synopsis of the poneroid complex of the family formicidae (Hymenoptera). Part II. Subfamily Myrmicinae. Bulletin of the institute of tropical agriculture, Kyushu Uniuersity 1991, 14: 88-93.

4. Majid Dejakam MS, MS Mosadeq PHD. Department of Entomology. Unpublished observation.

5. Edward Osborne Osborne Wilson. Pheidole Ant. Harvard university press Section Pheidole ants ISBN 0674002938 May 2002 411-412.

6. Harun Yahya (pen name) Adnan Oktar. The miracle in the ant. Pheidole spp 1995 609-14.

7. Richard Fagerlund B.C.E Integrated pest management environmental services.

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