Figure 1.
Flow diagram.
Table 1.
Demographic and clinical data of study participants at baseline.
Table 2.
Efficacy of treatment based on viability of embedded sand fleas.
Table 3.
Efficacy of treatment based on the morphological development of sand flea lesions.
Figure 2.
Photo series of two lesions located next to the nail rim of the fifth toe; treatment with dimeticone.
(A) Baseline: Two sand flea lesions in stage IIIa are located next to each other with the characteristic watchglass-like elevation. The abdominal cone is the circular brownish protrusion in the center of the lesions. (B) Day 3: The abdominal cones have changed in a brownish-black crust, the watchglass-like elevations have vanished and the lesions have dried out. Desquamation of the stratum corneum around the lesions has started. No signs of viability were detected. (C) Day 7: The appearance of the lesions has not changed; desquamation has slightly increased.
Figure 3.
Photo series of a lesion located at the base of the first toe; treatment with KMnO4.
(A) Baseline: A lesion in stage IIIa with a diameter of 10 mm at the base of the first toe. The abdominal cone is the circular brownish protrusion in the center of the elevation. The dermal papillae next to the lesion contain faecal material expelled by the parasite. (B) Day 3: The sand flea has expulsed several eggs (white oval dots). One of the eggs is in progress of being expelled. The appearance of the lesion has not changed. (C) Day 7: The lesion has retained its size and remains elevated. Recently excreted faecal material has spread into the dermal papillae next to the lesion, another indicator that the parasite remained viable.
Figure 4.
Photo series of a lesion documented by the digital handhold video microscope at 200 fold magnification; treatment with dimeticone.
(A) Baseline: Lesion in stage IIb. The abdominal cone is the circular brownish protrusion in the center. The cone is surrounded by a slightly elevated circle. The dark area on the right is part of the toe nail. (B) Day 3: The abdominal cone has changed in a brownish crust. The stratum corneum covering the embedded parasite has started to desquamate. No viability signs detectable. (C) Day 5: The rear cone has changed into a black crust. The desquamation has significantly enlarged. The uncovered intersegmental skin of the abdomen of the parasite has turned into dark-purple. (D) Day 7: The appearance of the lesion has remained similar; desiccation and desquamation have continued.
Figure 5.
Photo series of a lesion documented by the digital handhold video microscope at 200 fold magnification; treatment with KMnO4.
(A) Baseline: Lesion in stage IIIa. The abdominal cone is the circular brownish protrusion surrounded by the characteristic watchglass-like elevation. The curved line is faecal material of the parasite that has spread into dermal papillae. (B) Day 3: The embedded parasite has grown slightly and the convex elevation is more embossed. The abdominal cone is still brownish and shining. (C) Day 5: The appearance of the lesion has not changed. Faecal liquid is excreted through the abdominal cone and appears as a clear, light-reflecting “pond” on the top of the cone. (D) Day 7: The abdominal cone is still brownish and shining. The lesion has a convex double-rim appearance. Two viability signs (pulsation of the parasite and excretion of liquid) were present at this moment.
Figure 6.
Left and right foot after the application of the dimeticone and KMnO4, respectively.
The dark coloring of the right foot is due to KMnO4. The yellow jelly on the right foot is vaseline being in the process of dissolution.