Phthiriasis Palpebrarum – a rare case of pubic lice infestation on eyelashes

Katarzyna Borowska1, Tomasz Wasyłyszyn2

1Department of Histology and Embryology with Experimental Cytology Unit, Medical University of Lublin, 11 Radziwiłłowska, 20–080 Lublin, Poland
2Military Institute of Medicine in Warsaw, Department of Dermatology, Szaserów 128, 04-141 Warsaw, Poland

 

Corresponding author: Prof. Katarzyna Borowska, E-mail: k_borowska@wp.pl

 

Submission: 25.08.2017; Acceptance: 27.08.2017

How to cite this article: Borowska K, Wasyłyszyn T. Phthiriasis Palpebrarum – a rare case of pubic lice infestation on eyelashes. Our Dermatol Online. 2017;8(3e):e4.


ABSTRACT

Authors report a rare case of pubic lice infestation on eyelashes – Phthiriasis Palpebrarum. Phthiriasis palpebrarum is an ectoparasitosis in which Phthirus pubis, normally affecting pubic area infest the eyelashes. Due to the fact that eyelashes are not the optimal habitat of pubic lice the clinical picture is uncommon.

Key words: Phthiriasis palpebrarum, Phthirus pubis, human parasites, blepharitis, pubic louse.

 


INTRODUCTION

There are two main species of lice that parasitize humans: Pediculus humanus and Phthirus pubis. Phthirus pubis is commonly transmitted sexually and may infest pubic hair and perianal areas, legs, forearms, chest, eyebrows, axillary hair and beard. It also involves the eyelashes rarely [1,2]. The worldwide prevalence of Phthirus pubis is vast, usually described as 1-2% [3,4]. Although Phthiriasis species frequently infest the skin and hair, the infestation of eyelids is rare. Phthiriasis palpebrarum (PP) is sometimes difficult to identify because of the deep burrowing of the lice in the lid margin, and it is often misdiagnosed as atopic dermatitis or allergic blepharitis or blepharoconjunctivitis [5,6]. Moreover, the nits on the eyelashes may resemble the dried droplets of discharge present in blepharitis or conjunctivitis. The purpose of this study is to describe case of phthiriasis palpebrarum which is uncommonly reported in Poland.

 

CASE REPORT

40 years old female patient reported to the clinic with the artifacts on her eyelashes. These had a form of small, about 0.5 mm long elliptical gray – green structures attached to the proximal parts of the eyelashes.  Using strong magnifying glass authors were able to distinguish more details of these. Their thinner end was attached to the eyelash with the amorphous glue-like substance. The wider free end was more transparent and round (Fig. 1). On both lids there were several small red – blueish spots. The appearance of these artifacts was connected with serious itching, discomfort and sometimes even pain. Having the suspicion of PP, the authors tried to find a living parasite but they could not find any despite their efforts.

Figure 1: Status before treatment. Please note the red points, especially on the on upper eyelid.


The patient was previously treated by allergologist due to the allergic conjunctivitis. Prescribed medications containing mild corticosteroids and antibiotic; drops and ointments had no effect on the clinical picture nor on the symptoms. The artifacts described were interpreted at that moment as dried discharge from blepharitis or conjunctivitis. Later on patient was consulted by ophthalmologists who diagnosed PP but were not convinced about the treatment strategy i.e. proposed the physical removal of all eyelashes.
After examination in the clinic the patient was prescribed a cream containing 1% ivermectine with the indication to apply it twice a day on the edges of the eyelids and the eyelashes. On the control visits two weeks later authors noticed that all artifacts disappeared (Fig. 2).
No recurrence was found during 6 weeks of follow-up. Patient was advised to make blood test for the presence of sexually transmitted diseases (VDRL, HIV) as well as hepatitis viruses B and C.

Figure 2: Status post treatment. Note the disappearance of the spots and the nits.
 
DISCUSSION
 
Pubic louse is one of the oldest known human parasites. It is supposed that it evolved from other species which infested hairy body of Homo Sapiens predecessors about 3.3 million years ago [7]. The adult louse has a life span of about 1 month during which the female lays 7-10 eggs every day. From these eggs, so called “nits”, the nymphs hatch during the next 8 days. Nymphs require 8 days more to reach their sexual maturity, which makes them one of a fastest growing-up species. The latter facts are crucial to understand the authors’ thesis.
Pubic pediculosis or Phthiriasis in it's most typical location – the pubic area,  includes (except the nits and numerous parasites) other symptoms like numerous blue spots on the skin being in fact the reactions to the insect bite. Some spots could be found in PP too (Fig. 1), but these found in our present case were rather red. In fact the parasites themselves are a rare finding. Eyelashes are not an optimal habitat for Phthirus pubis. Tears and discharge produced by conjunctiva as a result of infestation probably kill most parasites soon after their early developed maturity. So probably does any ointment [8], like the one prescribed by allergologist, plugging respiratory paths of the lice. Since the authors were not able to detect any parasites, just their eggs, they hypothesize that most lice die soon after reaching their maturity and lying first eggs. Therefore clinical picture shows  eggs being attached to the eyelashes in a manner similar to grapes on the vine (Fig. 3). As the eyelashes grow new populations of nits appear in proximity of the eyelids. The older ones disappear as the nymphs hatch out; therefore the distal parts of the eyelashes bear no nits (Fig. 1 and 3). The key to the parasites population survival is their extremely short time to reach the sexual maturity.
Figure 3: The schematic showing the nits arrangement in Phthiriasis Palpebrarum. Please note the absence of the nits on the distal parts of the eyelashes. Compare with picture 1.

While physical eyelashes removal could be an obvious treatment it may not be accepted due to the cosmetic reasons. Suggested typical treatments, like malathion, pyrethrins with piperonyl butoxide, pyrethroids [8] might irritate the eyes. Thus the authors decided to administer topically 1% ivermectine preparation (Soolantra creme). While not being the “ophthalmological” the cream did not irritate the eyes despite being applied on the edge of the eyelids and surely having contact with conjunctiva. It was well tolerated and effective.

 

REFERENCES

1. Ko CJ, Elston DM. Pediculosis. J Am Acad Dermatol. 2004;50:1–12.
2. Ashraf M, Waris A, Kumar A, Akhtar N. A case of unilateral phthiriasis palpebrarum infestation involving the left eye. BMJ Case Rep 2014;2014,pii: Bcr2013203307.
3. Singh A, Tripathy K, Gupta N, Kale P, Verma N, Mirdha BR. Phthirus pubis in the eye. Indian J Med Microbiol. 2016;34:405-6.
4. Anderson AL, Chaney E. Pubic lice (Pthirus pubis): History, biology and treatment vs. knowledge and beliefs of US college students. Int J Environ Res Public Health. 2009;6:592-600.
5. Yi JW, Li L, Luo da W. Phthiriasis palpebrarum misdiagnosed as allergic blepharoconjunctivitis in a 6-year-old girl. Niger J Clin Pract. 2014;17:537-9.
6. Pinckney J II, Cole P, Vadapalli SP, Rosen T. Phthiriasis palpebrarum: a common culprit with uncommon presentation. Dermatol  Online  J. 2008;14:1–7.
7. Stefański W. Parazytologia weterynaryjna tom II, Państwowe Wydawnictwo Rolnicze i Leśne, Warszawa, 1970, str. 72
8. T Burns Breathnach, Neil Cox N. Rook's Textbook of Dermatology, 4 Volume Set, 8th Edition. Wiley-Blackwell 2013, 38.19-22 p. 1813-16.

 

Notes

Source of Support: Nil,

Conflict of Interest: None declared.

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