1. After a pedicure, this patient’s great toe became discolored. It is most probably:
d) Pseudomonas infection
The greenish-black color strongly suggests Pseudomonas infection, which was confirmed by culture. There was no evidence of hemorrhage into the nail plate or trauma and no nail polish was used. Fungus cultures and periodic acid–Schiff staining were negative. Treatment consists of removing the onycholytic nail plate (which usually occurs) and keeping the nail unit dry. A topical antibiotic is generally sufficient to clear the infection. Pseudomonas almost always causes onycholysis, occurring often with Candida, and may have a protective capacity against dermatophyte invasion.
References
Yang YS, Ahn JJ, Shin MK, Lee MH. Fusarium solani onychomycosis of the thumbnail coinfected with
Pseudomonas aeruginosa: report of two cases. Mycoses. 2011;54(2):168-171. doi:10.1111/j.1439-0507.2009.01788.x
Rigopoulos D, Rallis E, Gregoriou S, et al. Treatment of Pseudomonas nail infection with 0.1% octenidine dihydrochloride solution. Dermatology. 2009;218(1):67-68. doi:10.1159/000171816
2. This patient with scleroderma (on the right) has a nail plate showing a greater transverse than longitudinal dimension—the reverse of normal. Such a nail is referred to as:
e) Racket nail (brachyonychia)
When the nail plate is longer transversely than longitudinally, it is referred to as racket nail (ongle en raquette). It is associated with an abnormal distal phalanx and nail matrix with shortened digit. It may be familial, traumatic, idiopathic, or secondary to disease ultimately affecting the development of the nail plate. Such is the case in this patient with scleroderma. The collagen vascular disorder has resulted in partial phalanx destruction due to poor circulation. This, in turn, affects the nearby nail matrix, thus producing the abnormal nail plate. Pterygium inversum unguis and koilonychia have been previously discussed in the literature. Onychorrhexis is the increased longitudinal ridging and splitting of the nail plate. Clubbing is due to Lovibond angle exceeding 180˚, which is not the case here.
References
Balinchón Romero I, Ramos Rincón JM, Reyes Rabell F. Nail involvement in leprosy [in Spanish]. Actas Dermosifilograf. 2012;103(4):276-284. doi:10.1016/j.ad.2011.07.011
James WD, Berger TG, Elston DM, Odom R. Racket nails. In: James WD, Berger TG, Elston DM, Odom R, eds. Andrew’s Diseases of the Skin: Clinical Dermatology. 10th ed. Philadelphia, PA: Saunders Elsevier;2006:786.
Dr McMichael is professor and chair in the department of dermatology at Wake Forest Baptist Health in Winston-Salem, NC.
