Evaluation of the Effectiveness of a Silver-Impregnated Medical Cap for Topical Treatment of Nipple Fissure of Breastfeeding Mothers

Abstract

Objective:

This study evaluated the effectiveness of a medical topical treatment device named Silver Cap^® (Depofarma S.P.A., Mogliano Veneto, Treviso, Italy) for the treatment of nipple fissure in lactating women and its local tolerability, compared with the standard of care for nipple fissure treatment during breastfeeding.

Subjects and Methods:

From December 2013 to September 2014, we recruited 40 women for symptomatic nipple fissures during lactation. Participants were randomized into two groups: the Silver Cap group (20 women; group A) or the control group (20 women; Group B, standard of breastfeeding care). All participants received breastfeeding education provided by a board-certified lactation consultant. Group A was instructed to use the Silver Cap. Group B had a handbook with the standard of care for nipple treatment after each breastfeeding. Both groups received a questionnaire for a daily assessment. The duration of both treatments was 15 days. We performed a clinical evaluation on Days 0 and 2 and a follow-up by telephone on Day 7, and all participants underwent final evaluation face to face on Day 15. We performed photographic recording of the nipple on Day 0 and Day 15.

Results:

There were no statistical differences in follow-up between the two treatments at Day 2. There was a significant and a more rapid resolution of painful symptoms in the Silver Cap group compared with the control group (p<0.05) at Days 7 and 15. Treatment with Silver Cap was more appreciated by the participants than standard care (p<0.05). Four participants in the Silver Cap group and six in the control group dropped out of the study. No local or systemic reactions were reported following Silver Cap application.

Conclusions:

Results of treatment with Silver Cap were more effective than standard care of nipple fissure treatment in term of resolution of painful symptoms. It promoted the healing process of lesions, and it was well tolerated and accepted by participants.

Introduction

A fissure is defined as a perforation or ulceration of the nipple skin that occurs at any time of lactation. It mainly affects the nipple and areolar area, usually occurs as a clean cut, is painful, and sometimes can bleed or be covered with scabs and serum.¹ There are several predisposing factors: poor attachment to the breast, incorrect position of the baby during breastfeeding, incorrect sucking due to functional and organic causes, the nipple not properly compliant with lactation, poor hygiene of the nipple, atopic skin, or tight lingerie.^1–4 There was no correlation between the method of birth and nipple pain or damage.⁵

The incidence of nipple pain and/or fissures during breastfeeding is between 11% and 96%, according to published case series.^6–8 A recent study showed that 58% of women reported nipple damage during the first 8 weeks of breastfeeding.⁵ Differing support of women during the initiation of breastfeeding by health professionals and an underestimation of the problems related to beastfeeding⁹ could explain this great variability.

Treating nipple fissure and nipple trauma quickly is therefore an important factor in establishing successful breastfeeding by maintaining a pleasurable breastfeeding relationship between the mother and her infant¹⁰ and preventing complications such as mastitis or abscesses.¹

Nipple trauma is the main reason for early breastfeeding cessation.^6,11

Various interventions have been used to treat either nipple pain and/or trauma associated with breastfeeding. These include topical creams, solutions, or sprays, time-restricted breastfeeding, exposure of the nipple to dry heat or ultraviolet light and air-drying, pre- or postnatal breastfeeding education, breast protection shells, hydrogel, adhesive polyethylene film dressing, and distilled water.^6,11–13

A recent systematic review by Vieira et al.¹¹ on the several interventions for nipple trauma in breastfeeding mothers concluded that the best outcomes for the treatment of nipple trauma used lanolin (recommendation B, evidence level 2) and breastmilk (recommendation B, evidence level 2). However, the biggest study on 225 puerperal mothers by Mohammadzadeh et al.,¹⁴ cited in this review, questioned the efficacy of lanolin and highlighted the superiority of breastmilk.

Recent guidelines¹ recommend the use of breastmilk (skin repair activity of substances present in milk, including various growth factors^15,16) or purified lanolin in the treatment of nipple fissures, based on the principle of healing in moist environment. However, existing scientific studies^{11,12,17–19} do not permit conclusions to be drawn on the efficacy of these methods, which are based on practical experience (Good Clinical Practice).¹

The “moist wound healing” method was developed in 1962 by George Winter, in the biomedical engineering department at the Royal Orthopedic Hospital in Stanmore (Middlesex), United Kingdom. This treatment involves the application of “films or other materials” able to occlude the wound, make the environment hypoxic, prevent the permeation of microorganisms, and control the pain.²⁰

Current wound treatment methods use moisture to aid healing. A moist environment is critical for epithelization, the proliferation and migration of epithelial cells across the surface of a wound during healing. Nipple wounds also heal by this process.^13,21

Among natural measures, the usefulness of silver in assisting the reparative processes is known in some populations, including in the Mediterranean area: silver is a natural antibacterial and healing agent, known since ancient times.²² Although its use fell into disfavor with the discovery of modern antibiotics, it was recently reconsidered after episodes of antibiotic resistance. Several studies^23–29 have reported that silver ions are able to precipitate proteins of bacterial protoplasm, which are rendered nontoxic and are not systemically absorbed percutaneously.

The aim of this study was to evaluate the efficacy of Silver Cap^® (Depofarma S.P.A., Mogliano Veneto, Treviso, Italy), a cup-shaped medical device composed of trilaminate silver (99.9%) (Fig. 1), in controlling symptoms in lactating women with a confirmed diagnosis of nipple fissure, as well as its local tolerability. There are no clinical trials that have tested its efficacy and safety, but it has been marketed in Italy in pharmacies since 1998 and now online (www.depofarma.it/silvercap), and there are no reports of adverse reactions during its use.

FIG. 1.

The Silver Cap device.

Silver Cap is reusable and can be cleaned with water. Unlike using creams and ointments, using Silver Cap does not alter the taste and smell of breastmilk because no substances remain in the nipple once the device is removed. The cup's special design and the “scratch” on the inner side of the device promote a good latch to the nipple, keeping the environment moist and hypoxic. The “hypoxia” is beneficial to avoid the growth of aerobic bacteria. Hypersensitivity to silver is an absolute contraindication of its use.

Materials and Methods

This was an observational, prospective study.

Inclusion criteria were nipple fissure, age between 18 and 40 years, singleton birth, no prior breastfeeding experience, and written informed consent.

Exclusion criteria were use of psychotropic drugs, antibiotics, antifungals, cortisone, or immunomodulating substances, hypersensitivity to silver, breast infections, and mammary diseases not related to breastfeeding.

The participants enjoyed good health, and all gave a written informed consent to the study after informative interview.

A fissure was defined as a perforation or ulceration of the nipple skin that occurs at any time during lactation.

As this was a pilot study with a small sample size (40 participants), we wanted to compare the safety and efficacy of Silver Cap with a natural method of treatment of nipple fissure (standard care of nipple, as well as nipple treatment with breastmilk after each breastfeeding). “Standard care” means the standard method of adequate personal hygiene and care of the nipple, as well as instructions regarding the proper placement of the child during feeding in order to create optimal conditions for breastfeeding, which are given to all women when consulting with our neonatologist (the woman is given a sheet with the advice above), as recommended in recent guidelines.¹ Women were adequately informed, according to the guidelines, on the possibility of active treatment with breastmilk or lanolin, considered at the time as first-line treatments.¹ Women in the control group were treated exclusively with breastmilk, and women had decided freely to participate in the study, applying only breastmilk throughout the period of the evaluation without using other creams or ointments.

Allocation was performed randomly using a personal computer program (www.servizi.regione.emilia-romagna.it/generatore): Group A used Silver Cap, whereas women in Group B, being the control group, were educated by the lactation consultant of our Neonatal Care Unit with the standard care of the nipple, as well as nipple treatment with breastmilk after each breastfeeding.

Those women in the two groups who for more than 2 days did not use Silver Cap in Group A or breastmilk in Group B were considered to have discontinued the study.

All participants, as mentioned in the informed written consent, could stop the study prematurely at their request, if justified or not, if adverse events occurred, or there was low compliance or poor responsiveness to treatment.

Each participant was monitored for 15 days. The study started at Day 0 (Visit 1) with the recruiting visit that confirmed the nipple fissure diagnosis. We performed a photographic recording to all participants at the first visit and at Day 15.

The participants completed a questionnaire (on Days 0, 2, 7, and 15) that evaluated the state of the three main parameters of nipple fissure (pain, bleeding from the nipple, and fissures) using an 11-point scale, from 0 to 10. This scale was delivered at the time of Visit 1 to the participants of the study, who were instructed on its use.

Thus we studied the participants by clinical evaluation on Day 2 (Visit 2), by telephone interview on Day 7, and face to face on Day 15 (Visit 3). The checkup on Day 15 was carried out at our Neonatal Care Unit by clinical evaluation and photographic assessment.

The consultant, who was aware of the basic photographic principles, using a digital camera, took the photographs. The registration followed the criteria of clinical³⁰ photography: we tried to faithfully reproduce in follow-up the setting, lighting, and placement used previously.

A numerical rating scale (Fig. 2) based on 11 points (0–10) has been used for the assessment of pain.^31,32 This scale assigned the value of 0 to the absence of pain and the value of 10 to the worst pain imaginable.

FIG. 2.

Pain score: categorization of the Numerical Rating Scale.

For assessment of bleeding from the nipple, we considered the following evaluation criteria: 0=no bleeding during the breastfeeding; 1–3=the participants occasionally bled during the breastfeeding; 4–6=the participants bled at least once a day; and 7–10=the participants bled for each breastfeeding.

Severity of the nipple fissures was assessed in millimeters by a millimeter scale ruler and magnifying glass. The biggest size of the lesion was assessed as 10 mm.

For the assessment of symptoms reported by participants on a 11-point scale, values of ≤3 were considered lack of or resolution of the symptoms. Furthermore, we considered the fissure resolved if we observed its disappearance.

Maternal satisfaction (compliance) with treatment was assessed at the end of the study using a scale to 1–5, as follows: 1=insufficient, 2=sufficient, 3=moderate, 4=good, and 5=excellent.

In addition, we assessed in the Silver Cap group local tolerability by monitoring any irritations in course of treatment. We asked participants to mark on a tiered scale the appearance of any adverse reactions as a result of the use of the Silver Cap device, as follows: 1=appearance of mild erythema following application of the device, 2=appearance of mild erythema and itching as a result of application of the device, 3=onset of mild erythema+edema+itchy papules, 4=appearance of considerable erythema+edema+itchy papules, and 5=appearance of considerable erythema+papules+painful vesicles due to application of the device. The tolerability was evaluated daily by participants, who were advised to inform us immediately in the event of adverse reactions before continuing the study.

Regarding the practice of breastfeeding, expressed breastmilk was not used. All women were instructed to not stop exclusive breastfeeding. No women expressed milk, according to our suggestions.

Ethical committee approval

The Ethics Committee of ASL N.1 Sassari, Sassari, Italy approved our study. The number given to the study by the ethics committee of Azienda Ospedaliero-Universitaria of Sassari (Italy) was 1179L/2014.

All participants were adequately informed about the development and the program of the study and signed in duplicate a proper informed consent.

Statistical analysis

The sample size was not computed because it was a pilot study carried out to assess differences between individuals treated and not treated. Being the first study ever conducted in the scientific literature, it was not possible to state any statistical assumptions on the sample size of the current study.

Measured values were expressed as mean and standard deviation. The comparison of variables was carried out using Fisher's test. For all statistical analysis, the significance level of the test was evaluated at p<0.05. The statistical software used for the analysis was STATA^® version 13 (StataCorp, College Station, TX).

Results

The characteristics of the participants are shown in Table 1. Statistical analysis showed no differences between the two groups.

Table 1.

Characteristics of the Study Population

	Group A (Silver Cap) (n=20)	Group B (control) (n=20)	p value
Age (years) [mean (SD)]	31.8 (5.1)	31.4 (6.3)	NS
Age of infants ≥39 weeks of gestation	100%	100 %	NS
Height (cm) [mean (SD)]	162.0 (5.9)	163.6 (4.4)	NS
Weight (kg) [mean (SD)]	72.9 (10.3)	70.1 (8.6)	NS
BMI (kg/m²) [mean (SD)]	27.8 (4.1)	26.2 (2.7)	NS
Race (white) (%)	100%	100%	NS
Parity [median (IQR)]	0.5 (0–1)	0.5 (0–1)	NS
Severity score (Visit 1) [n (%)]^a			NS
None	—	—
Mild	—	—
Moderate	17 (85)	19 (95)
Severe	3 (15)	1 (5)
Breastfeeding practices	Exclusive breastfeeding	Exclusive breastfeeding	NS

Pain, bleeding, and fissures.

BMI, body mass index; IQR, interquartile range; NS, not significant; SD, standard deviation.

We assessed 86 women who complained about difficulties in breastfeeding in the period from September 2013 to December 2014.

Thirty-eight out of the 86 (44.2%) were excluded: 34 had no nipple fissures, two women were excluded based on age (one was a teenager, and one was >40 years old), a woman reported an allergy to silver, and one participant took corticosteroids due to rheumatoid arthritis. Forty-eight of the 86 (56.8%) reported nipple fissures. Among the 48, eight women refused to participate in the study.

Table 2 reports the severity of the lesion based on a score that represents the sum of all three variables: pain, bleeding, and nipple fissures. We called this the Severity Score (none=0, mild=1–10, moderate=11–20, and severe=≥ 21). We included only women with a moderate/severe score.

Table 2.

Severity Score

Classification	Score
None	0
Mild	1–10
Moderate	11–20
Severe	≥21

The severity score is scaled on a score that represents the sum of all three variables: pain, bleeding from the nipples, and fissures. Pain is graded on a numerical rating scale of 0–10. Bleeding from the nipple is graded on a scale of 0–10. Fissure length has a maximum of 10 mm.

Thus we have included in the study 40 participants with symptomatic nipple fissures during lactation: 20 allocated to the Silver Cap group (Group A) and 20 to the control group (Group B) (see Fig. 3 for a flow chart of participation).

FIG. 3.

Flow chart of participation.

The results of the study are shown in Tables 3 and 4.

Table 3.

Results Reported for the Two Treatment Groups for Pain, Bleeding, and Fissures on Day 2

	Number (%)
Variable, evaluation on Day 2	Group A (Silver Cap) (n=20)	Group B (control) (n=20)	p value
Pain			1.0
Mild (NRS 1–3)	0 (0.0)	0 (0.0)
Moderate (NRS 4–6)	7 (35.0)	6 (30.0)
Severe (NRS 7–10)	13 (65.0)	14 (70.0)
Bleeding			0.86
Mild (1–3)	8 (40.0)	10 (50.0)
Moderate (4–6)	3 (15.0)	1 (5.0)
Severe (7–10)	1 (5.0)	1 (5.0)
Fissures			1.0
Mild (1–3 mm)	1 (5.0)	1 (5.0)
Moderate (4–6 mm)	17 (85.0)	18 (90.0)
Severe (7–10 mm)	2 (10.0)	1 (5.0)

NRS, numerical rating scale.

Table 4.

Results Reported for the Two Treatment Groups on Pain, Bleeding, Fissures, and Satisfaction (Compliance)

Variable, days of treatment	Group A (Silver Cap)	Group B (control)	p value
Pain			0.035
Resolved Day 7	11/16 (69)	3/14 (21)
Resolved Day 15	4/16 (25)	7/14 (50)
Bleeding			0.586
Resolved Day 7	15/16 (94)	12/14 (86)
Resolved Day 15	1/16 (6)	2/14 (14)
Fissures			0.27
Resolved Day 7	11/16 (69)	7/14 (50)
Resolved Day 15	5/16 (31)	5/14 (38)
Interruption	4/20 (20)	6/20 (30)	0.465
Satisfaction			0.035
Insufficient	—	—
Sufficient	—	2/14 (14)
Moderate	4/16 (25)	5/14 (36)
Good	2/16 (12)	5/14 (36)
Excellent	10/16 (63)	2/14 (14)

Data are number of subjects/total number of subjects (%).

There were no statistical differences with regard to pain, bleeding, and fissures in follow-up on Day 2 (Table 3).

As for the painful symptoms, 11 of 16 participants (69%) in the Silver Cap group reported disappearance of subjective pain in 7 days, versus three of 14 participants (21%) in the control group. Four of 16 (25%) participants in the Silver Cap group reported disappearance of subjective pain in 15 days of treatment, versus seven of 14 (50%) in the control group. One (6%) participant in the Silver Cap group reported persistent painful symptoms, versus four of 14 (29%) of participants in the control group. Silver Cap application showed a more rapid resolution of painful symptoms compared with traditional treatment (p<0.05).

With regard to the evaluation of bleeding, 15 of 16 participants (94%) in the Silver Cap group reported resolution within 7 days of treatment, and one of 16 participant (6%) reported resolution within 15 days. In the control group, 12 of 14 participants (86%) reported resolution at 7 days, and two of 14 participants (14%) did so in 15 days.

With regard to the resolution of fissures, 11 of 16 participants (69%) in the Silver Cap group had a resolution of symptoms within 7 days of treatment, versus seven of 14 (50%) in the control group. Five of 16 participants (31%) in the Silver Cap group and five of 14 participants (36%) in the control group, instead, showed a 15-day resolution; in two of 14 participants (14%) in the control group we reported persistence of the nipple fissure at 15 days of treatment.

Four of 20 (20%) participants in the Silver Cap group discontinued treatment: one participant for intercurrent maternal problems (mastitis) on Day 3 and one for neonatal problems (hydrocephalus) on Day 4; one participant did not respond to the telephone call on Day 7 and did not come to the final visit on Day 15; and one participant discontinued the study due to excessive subjective pain on Day 5.

Six of 20 participants (30%) in the control group discontinued treatment: two participants did not respond to a telephone call on Day 7 and did not come to the final visit; the remaining four participants discontinued the study due to excessive pain (two women on Day 4 and two on Day 5). Two of these four participants used an alternative treatment to resume breastfeeding such as tocopherol oil (vitamin E).

There was evidence that women were more likely to be satisfied with treatment with the Silver Cap device than with standard care.

Figure 4A shows the nipple fissure on Day 0 of Subject A. Figure 4B shows the resolved nipple fissure at Day 15 of the same subject after using Silver Cap treatment.

FIG. 4.

Subject A. (A) Nipple fissure on Day 1. (B) Resolved nipple fissure at Day 15 after using Silver Cap treatment.

Figure 5A shows the nipple fissure on Day 0 of Subject B. Figure 5B shows the resolved nipple fissure on Day 15 of the same subject after using Silver Cap treatment.

FIG. 5.

Subject B. (A) Nipple fissure at Day 1. (B) Resolved nipple fissure at Day 15 after using Silver Cap treatment.

With regard to the evaluation of local tolerability of the Silver Cap device, none of the women reported significant topical or systemic reactions following application of the device.

Discussion

Recommendations for standardized treatment of breast-related diseases during breastfeeding are required to optimize the assistance to women and ensure a uniform course of action,⁹ aimed mainly at prevention of complications.^1,33,34 Currently there is no evidence that demonstrates the effectiveness of a specific treatment.¹ The use of products for prevention of nipple fissure is not useful and could be counterproductive.^1,19

Many studies^11,12,35 on the prevention and treatment of nipple fissures and mammary lesions in the course of nursing had an inadequate sample size, and most, as well, showed bias.

The use of breastmilk or purified lanolin in the treatment of nipple fissures is based on the principle of healing in a moist environment according to recent guidelines,¹ but the results of these existing studies^{11,12,17–19} do not permit definitive conclusions because they are based only on practical experience.

No study has so far evaluated the effectiveness of the Silver Cap device.

Our study, despite the small sample size, showed a more rapid disappearance of symptoms and a more rapid healing in participants who used the Silver Cap device compared with controls, with good acceptability of treatment.

This pilot study allowed us to hypothesize that Silver Cap prevents the entry of microorganisms and also provides a mechanical covering, in order to protect the nipple from possible trauma.

Silver Cap is like all advanced wound dressings, which are safe, do not contain toxic elements, and are hypoallergenic. Thanks to its patented trilaminate, Silver Cap acts locally, and no silver is absorbed systemically, so there are no systemic drug interactions.

We think that the healing action of Silver Cap is due to a direct action of silver ions, as well as to an indirect effect of the device, which creates a hypoxic and moist microenvironment.

Silver Cap treatment is safe and efficacious, but further studies with bigger sample sizes are necessary to confirm our preliminary data.

A limitation of the study was the cost of Silver Cap, which ranges from 34.00 to 44.80 Euros (38.36 to 53.77 U.S. dollars) according to sellers. In contrast, Silver Cap can be cleaned, preserved, and reused in subsequent pregnancies. Another limitation is that the Silver Cap was not compared with a group receiving lanolin.

In conclusion, this study showed a more rapid resolution of painful symptoms, of bleeding, and of nipple fissures in participants who used the Silver Cap device compared with the control group. Treatment with Silver Cap was more appreciated than traditional treatment. No participants reported local or systemic reactions after treatment with Silver Cap.

A larger trial with assessment blinded to study group is required to confirm the results of this pilot study.

Footnotes

Acknowledgments

We thank Prof. Giovanni Sotgiu, Professor of Medical Statistics at the Department of Biochemical Sciences, Sassari University, Sassari, Italy, for statistical analysis of the data. DepoFarma provided free of charge the Silver Cap devices.

Disclosure Statement

No competing financial interests exist.

A.M. and M.G.S. recruited the women. G.C., F.D., M.D.P., and S.D. collected data.

References

Jacobs

, Abou-Dakn

, Becker

, et al. S3-Guidelines for the treatment of inflammatory breast disease during the lactation period. AWMF Guidelines, Registry No. 015/071 (short version) AWMF Leitlinien-Register Nr. 015/071 (Kurzfassung). Geburtshilfe Frauenheilkd, 2013; 73:1202–1208.

Inch

, Fisher

. Breastfeeding: Early problems. Pract Midwife, 2000; 3:12–15.

Tait

. Nipple pain in breastfeeding women: Causes, treatment, and prevention strategies. J Midwifery Womens Health, 2000; 45:212–215.

Huml

. Sore nipples. A new look at an old problem through the eyes of a dermatologist. Pract Midwife, 1999; 2:28–31.

Buck

, Amir

, Cullinane

, et al. Nipple pain, damage and vasospasm in the first eight weeks postpartum. Breastfeed Med, 2014; 9:56–62.

Brent

, Rudy

, Redd

, et al. Sore nipples in breast-feeding women: A clinical trial of wound dressings vs conventional care. Arch Pediatr Adolesc Med, 1998; 152:1077–1082.

Ziemer

, Paone

, Schupay

, et al. Methods to prevent and manage nipple pain in breastfeeding women. West J Nurs Res, 1990; 12:732–743.

Ziemer

, Pigeon

. Skin changes and pain in the nipple during the 1st week of lactation. J Obstet Gynecol Neonatal Nurs, 1993; 22:247–256.

Amir

, Ingram

. Health professionals' advice for breastfeeding problems: Not good enough!. Int Breastfeed J, 2008; 3:22.

10.

Svensson

, Velandia

, Matthiesen

, et al. Effects of mother-infant skin-to-skin contact on severe latch-on problems in older infants: A randomized trial. Int Breastfeed J, 2013; 8:1.

11.

Vieira

, Bachion

, Mota

, et al. A systematic review of the interventions for nipple trauma in breastfeeding mothers. J Nurs Scholarsh, 2013; 45:116–125.

12.

Page

, Lockwood

, Guest

. Management of nipple pain and/or trauma associated with breast-feeding. JBI Rep, 2003; 1:127–147.

13.

Ziemer

, Cooper

, Pigeon

. Evaluation of a dressing to reduce nipple pain and improve nipple skin condition in breast-feeding women. Nurs Res, 1995; 44:347–351.

14.

Mohammadzadeh

, Farhat

, Esmaeily

. The effect of breast milk and lanolin on sore nipples. Saudi Med J, 2005; 26:1231–1234.

15.

Read

, George-Nascimento

. Epidermal growth factor: Physiological roles and therapeutic applications. Biotechnol Ther, 1990; 1:237–272.

16.

Read

, Francis

, Wallace

, et al. Growth factor concentrations and growth promoting activity in human milk following premature birth. J Dev Physiol, 1985; 7:135–145.

17.

Tanchev

, Vulkova

, Georgieva

, et al. Lansinoh in the treatment of sore nipples in breastfeeding women [in Bulgarian]. Akush Ginekol (Sofiia), 2004; 43(Suppl 3):27–30.

18.

Abou-Dakn

, Fluhr

, Gensch

, et al. Positive effect of HPA lanolin versus expressed breastmilk on painful and damaged nipples during lactation. Skin Pharmacol Physiol, 2011; 24:27–35.

19.

Pugh

, Buchko

, Bishop

, et al. A comparison of topical agents to relieve nipple pain and enhance breastfeeding. Birth, 1996; 23:88–93.

20.

Winter

. Formation of scab and rate of epithelialization of superficial wound in the skin of the young domestic pig. Nature, 1962; 193:293–294.

21.

Cable

, Stewart

, Davis

. Nipple wound care: A new approach to an old problem. J Hum Lact, 1997; 13:313–318.

22.

Alexander

. History of the medical use of silver. Surg Infect (Larchmt), 2009; 10:289–292.

23.

, Hayter

, Chang

, et al. A systematic review of silver-releasing dressing in the management of infected chronic wounds. J Clin Nurs, 2008; 17:1973–1985.

24.

Yamanaka

, Hara

, Kudo

. Bactericidal actions of a silver ion solution on Escherichia coli, studied by energy-filtering transmission electron microscopy and proteomic analysis. Appl Environ Microbiol, 2005; 71:7589–7593.

25.

McDonnell

, Russell

. Antiseptics and disinfectants: Activity, action, and resistance. Clin Microbiol Rev, 1999; 12:147–179.

26.

Leaper

. Silver dressings: Their role in wound management. Int Wound J, 2006; 3:282–294.

27.

Caruso

, Foster

, Blome-Eberwein

. Randomized clinical study of hydrofiber dressing with silver or silver sulfadiazine in the management of partial-thickness burns. J Burn Care Res, 2006; 27:298–309.

28.

Landsdown

ABG

. Pharmacological and toxicological profile of silver as an antimicrobial agent in medical devices. Adv Pharmacol Sci, 2010; 2010:910686.

29.

Berger

, Spadaro

, Chapin

, et al. Electrically generated silver ions: Quantitative effects on bacterial and mammalian cells. Antimicrob Agents Chemother, 1976; 9:357–358.

30.

Vallarelli

. Criteria for submitting photos. An Bras Dermatol, 2011; 86:212–214.

31.

Hjermstad

, Fayers

, Haugen

, et al. Studies comparing Numerical Rating Scales, Verbal Rating Scales, and Visual Analogue Scales for assessment of pain intensity in adults: A systematic literature review. J Pain Symptom Manage, 2011; 41:1073–1093.

32.

Williamson

, Hoggart

. Pain: A review of three commonly used pain rating scales. J Clin Nurs, 2005; 14:798–804.

33.

Sayyah Melli

, Rashidi

, Delazar

, et al. Effect of peppermint water on prevention of nipple cracks in lactating primiparous women: A randomized controlled trial. Int Breastfeed J, 2007; 2:7.

34.

Lawrence

, Lawrence

. Breastfeeding: A Guide for the Medical Profession, 6^th edition. Elsevier Science, New York, 2005.

35.

Morland-Schultz

, Hill

. Prevention of and therapies for nipple pain: A systematic review. J Obstet Gynecol Neonatal Nurs, 2005; 34:428–437.