Pustular Psoriasis of Pregnancy with Acrodermatitis Continua of Hallopeau.

Sir,

Generalized pustular psoriasis of pregnancy (GPP) is a rare entity occurring usually in the third trimester presenting with generalized plaques with peripheral pustules initially from the intertriginous areas disseminating to the rest of the body.

The presence of acrodermatitis continua suppuritica of Hallopeau is a rare entity to occur in association with GPP of pregnancy characterized by the presence of pustules and erythema commonly on the fingers and toes and rarely involving the palms and nails.

Presenting here, an intriguing case of 28-year-old primigravida, in her third trimester with GPP of pregnancy with acrodermatitis continua of Hallopeau (ACH) involving the nails, hands and feet treated successfully with topical steroids.

Pustular psoriasis of pregnancy (PPsP) is an unusual pustular dermatosis of pregnancy. The entity presents itself with reddish plaques and patches with peripheral studded pustules and scaling, usually in the early third trimester of pregnancy. The disease begins in groin folds, axilla, and such intertriginous areas and eventually spread to the rest of the body sparing palms and soles. ACH is a variant of GPP characterized by multiple pustules with scaling and erythema, usually constrained to one or two digits distally.[12] Very few cases have been reported on PPsP and its association with ACH is documented still scarcely. Whether PPsP is a separate disease or a type of psoriasis triggered by pregnancy is still a point of debate.

A 28-year-old primigravida presented with extensive erythematous, pruritic plaques with peripheral scaling and sterile pustules in her early third trimester since 2 weeks suggestive of PPsP [Figure 1a and c]. Associated symptoms of fever with chills and fatigue were noted. The lesions began in the inner thighs and in due course involved the extremities, abdomen, upper trunk, and forehead. The patient had no personal or family history of psoriasis. The patient had no relevant drug history, which could have possibly triggered psoriasis.

Figure 1

(a) Extensive erythematous, pruritic plaques with peripheral scaling and sterile pustules suggestive of pustular psoriasis of pregnancy. (b) Characteristic pustular eruption with erythema involving the distal part of the fingers and thumb giving the “lakes of pus” appearance suggestive of acrodermatitis continua of Hallopeau. (c) Peripheral sterile pustules on a scaly erythematous plaque in pustular psoriasis

On examination, both the hands showed characteristic pustular eruption with erythema involving the distal part of the fingers and thumb suggestive of ACH [Figure 1b]. The areas also involved the nail folds and the nail bed of the thumb, index finger and the middle finger of both hands and the great toe of right leg, which showed coalesced pustules giving the “lakes of pus” appearance, finally involving the dorsum of the hands and feet.

The fungal and bacterial culture of the pus was negative for both. The patient had normal laboratory findings along with calcium, phosphate, and albumin levels. There were no signs of hypoparathyroidism on examination and blood investigations. The blood investigations were carried out every 3 weeks. The antenatal examinations of the patient, which were carried out at regular intervals, were normal with no signs of placental insufficiency.

The patient was immediately put on Class I topical steroids (clobetasol dipropionate) under occlusion, and regular hydrogen peroxide washes for the hands and nails. Oral antibiotics were administered to avoid secondary bacterial infection.

The patient responded remarkably to the combination of topical steroids and oral antibiotics alone without further intervention or treatment resolving about 70% of pustules in 2 weeks [Figure 2]. However, few new pustules appeared at the end of 2 weeks on the forehead, which again resolved with the same continued treatment.

Figure 2

Healed lesions of pustular psoriasis and acrodermatitis continua of Hallopeau after 8 days treatment with topical steroids

During the treatment time, the only complication seen was reduced fetal movements, which on further investigating with an ultrasonography was normal.

PPsP is a sterile pustular dermatoses predominantly taking place in the last trimester of pregnancy and infrequently in puerperium and nonpregnant women. It is known to reappear in consequent pregnancies. Recurrence is common and has been reported in up to nine successive pregnancies and on the use of oral contraceptive.[3] Even though it follows an unknown etiology, hypocalcemia, hypo-parathyroidism, stress, and bacterial infection are some reported triggering factors. The majority of the patients do not have any personal as well as family history of psoriasis.[2]

During the course of PPsP, anti-elastase activity drops to very low levels, associated with total saturation of epidermal anti-HLE activity. Reduced amount of epidermal skin-derived antileucoproteinase plays a role in disrupting the equilibrium between elastase and its inhibitor, resulting in the formation of pustules. This mechanism of pustule formation suggests a final common pathway for both to GPP and PPsP.[4]

Clinically, the patient presents with erythematous plaques, peripheral scales, and sterile pustules initially in the intertriginous areas. Systemic symptoms such as fever, diarrhea, delirium, organ failure, malaise, diarrhea, and pain may be present. GPP has been associated with sepsis, tetany secondary to hypocalcemia, electrolyte imbalances, placental insufficiency, intrauterine growth retardation, premature delivery and increased fetal morbidity and mortality. The generalized form (von Zumbusch psoriasis) is much more serious, and this form can even be fatal. Differential diagnoses include subcorneal pustular dermatosis, acute generalized exanthematous pustulosis, pemphigoid gestationis, and bullous impetigo should be considered.[56]

ACH is a rare acropustular sterile eruption on an erythematous base with paronychia, anonychia, onychodystrophy, and atrophic skin changes.[17] Osteolysis of the distal phalanges of the affected fingers and toes may develop over a period of time. The pustules coalesce to form “lakes of pus” which eventually spreads to the dorsum of the hands and feet. It is a variant of pustular psoriasis, sometimes also considered as a separate entity, and occasionally manifests along with PPsP.[1]

The histopathological findings of PPsP are similar to pustular psoriasis consisting of focal parakeratosis, acanthosis, elongated rete ridges, subcorneal and intraepidermal spongiform pustules containing neutrophils, Munro microabscesses, and perivascular and papillary dermal infiltration of lymphocytes and neutrophils.[26] Acrodermatitis continua characteristically show subcorneal neutrophilic pustules.[1]

Early treatment of PPsP is crucial for better maternal and fetal outcomes. Prednisolone 1 mg/kg/day should be started as soon as possible. In refractory cases, narrow band ultraviolet B can be added.[8] Postpartum treatments with cyclosporine usually shows a great response.[910] In cases of treatment with ACH, studies have shown success with intravenous infliximab, oral methotreaxate, and sulfasalazine. Topical tacrolimus has been tried to alleviate cutaneous manifestations.[11] Oral zinc 50 mg twice daily has also shown great results in treating pustular psoriasis in the elderly.[12]

PPsP whether a separate entity or a variant of general pustular psoriasis is still a matter of debate and only 200 cases have been documented in the last 32 years.[3] It is considered as a variant of GPP, triggered by pregnancy, which resolves after postpartum and recurs with pregnancy usually.[13] ACH and PPsP are known associations but are reported rarely. ACH even if considered as a variant of pustular psoriasis, is nonresponsive to common anti-psoriatic medications. There have been reports of ACH evolving into GPP, but this is the first study reporting a case of ACH with pustular psoriasis in pregnancy.[14] Oral corticosteroids are the first choice in the treatment of PPsP.[3] We hereby reported a case of PPsP with normal calcium levels, with ACH, treated only with topical corticosteroids.

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