Acral pebbles: A novel manifestation of partially treated syphilis.

Atypical manifestations in syphilis are known and pose a diagnostic dilemma. Early suspicion, timely investigations, diagnosis, and treatment, is the key to successful management. We report a patient of secondary syphilis, who presented as genital ulcer and small pebbles like eruptions on the palmar aspect of his fingers.

INTRODUCTION

The clinical manifestations of syphilis often lead to misdiagnosis or delayed diagnosis.[12] We report an unusual association of syphilis with “acral pebbles.”

CASE REPORT

A 40-year-old man presented with onset of sudden and persistent asymptomatic lesions on both palms for 2 weeks. He was apparently alright 4 weeks ago when he noticed a single large painless ulcer without discharge on his penile foreskin. He took treatment from a local family practitioner (including tablets and injections; details not known) which resulted into partial resolution of the genital ulcer. This was followed by asymptomatic eruptions on palms 3 weeks later. He admitted having unprotected sexual intercourse with an unknown female partner 3 months back.

On examination, a well-defined, solitary, partially healed, indurated ulcer with a clean base was seen on the prepuce [Figure 1a]. The distal palmar surface of fingers showed multiple asymptomatic bilateral grayish-white well-defined discrete firm, oval, and spherical papules [Figure 1b and c]. A few discrete papules were also present on thenar eminences of both the palms. Bilateral nontender inguinal and deep cervical lymphadenopathy was noted. There were no oral mucosal or ocular or perianal lesions.

Figure 1

(a) A partially healed, indurated ulcer with a clean base on the prepuce. (b) and (c) The distal palmar surface of fingers showed asymptomatic well-defined, discrete, firm, multiple bilateral grayish-white, oval, and spherical papules

As he was a manual laborer working in a farm, we considered clinical diagnoses of secondary syphilis, dermatophytosis, contact dermatitis, occupational trauma, and drug rash. Topical emollients and steroid cream given by general practitioner were not helpful in clearing the eruptions.

KOH microscopy was negative. The rash appeared 14 days after the last tablet consumed. Careful history taking did not point to any specific contact allergen or occupational disease as a cause.

Venereal disease research laboratory test (VDRL) was positive in 1:4 dilution. Cerebrospinal fluid examination could not be done. Test for HIV antibodies and hepatitis B were negative. Warthin starry stain did not demonstrate the organisms. Hence, we were confused if the VDRL was false positive.

We went back to more detailed clinical examination. Buschke-Ollendorff's sign was positive on some of these lesions. Unilateral left epitrochlear lymph node was enlarged and nontender.

A biopsy specimen from the skin lesions on finger revealed hyperkeratosis and intimal thickening of dermal blood vessel walls with narrowing of lumen amidst abundant fibrocollagenous tissue in the dermis and a sparse mixed cellular infiltrate of plasma cells and lymphocytes [Figure 2]. Treponema pallidum hemagglutination (TPHA) test was positive in the titers of 1:1200.

Figure 2

Skin biopsy revealed intimal thickening of dermal blood vessel walls with narrowing of lumen amidst abundant fibrocollagenous tissue in the dermis and a sparse mixed cellular infiltrate of plasma cells and lymphocytes

Based on clinical findings and investigations, we strongly considered a diagnosis of atypical secondary syphilis. The patient was treated with a single shot of intramuscular injection Benzathine penicillin (2.4 megaunits) with rapid resolution of the palmar lesions within a week [Figure 3] and also the penile ulcer healed with scarring completely by 10 days.

Figure 3

Dramatic resolution of finger eruptions after 1 week of penicillin injection

The patient was counseled and observed further. The VDRL test was still positive in 1:2 titers at the end of 6 months. There was no recurrence of penile or palmar or acral eruptions. There was no further occurrence of fresh lymphadenopathy or mucosal lesions. The patient declined further treatment. We explained him the importance of follow-up and treatment. However, he was lost to the follow-up.

His wife was also examined, and an asymptomatic vulval ulcer on mucosal aspect of her left labia [Figure 4] with bilateral inguinal nodes was revealed in clinical examination. She initially declined for the investigations and treatment. After repeated counseling, she was treated with benzathine penicillin injection, which led to complete resolution the vulval ulcer.

Figure 4

The arrow depicts healed circular asymptomatic vulvar ulcer on left labia majora of patient's wife

DISCUSSION

Our case illustrates the importance of careful history taking and clinical examination. Atypical manifestations must be kept in mind while dealing with confusing and incomplete clinical picture.[123] The relevance of VDRL titers should be assessed in the light of history and clinical findings. The weakly positive titers of VDRL test may be due to antibiotic courses by family practitioners, which are often inadequate, though this may lead to partial resolution of syphilis.[3] Our diagnosis was confirmed by reactive TPHA and dramatic resolution of penile ulcer and eruptions on the hand within a week and no recurrence of the genital ulcer and the palmar eruptions.

Both, the patient and his wife, were counseled about the infectious nature of the disease. It was utmost important to examine the spouse, though she was reluctant. Once asymptomatic vulval ulcer was noted in her, it was also extremely important to convince her for the treatment. We believe this prevented the further disaster in her.

The palmoplantar lesions known manifestation of secondary syphilis with maculopapular and scaly lesions predominating the clinical picture. Annular syphilide is known in secondary syphilis. Other rare manifestation, which has been reported is syphilitic Moreira et al.[2] which presents as erythematous plaques with thick scaling.

Finger pebbles is a known manifestations in sportsmen engaged in playing basketball and volleyball. These are said to the result of subcute or chronic dermatitis resulting from repeated mechanical trivial trauma with or without an element of contact dermatitis.[45] Clinical manifestations in our case mimicked acral pebbles, which actually turned out to be a manifestation of secondary syphilis.

Pebbles on dorsa of fingers and hand, typically affecting knuckles is said to a characteristic of diabetes.[67] However, this condition is quite different than those described in the athletes engaged in various sports.

In summary, we describe acral pebbles as an unusual manifestation of secondary syphilis. This finding is hitherto unreported on PubMed in English language, to the best of our knowledge.

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Conflicts of interest

There are no conflicts of interest.