SALT II: A new take on the Severity of Alopecia Tool (SALT) for determining percentage scalp hair loss

To the Editor: The percentage scalp surface area (SSA) involved in various hair loss disorders is of interest for a variety of reasons including potential staging of a given condition, prognostic implications for hair regrowth, amount of drug application necessary for treatment, and efficacy assessments. We previously published a tool for determining degree of hair loss based on the percentage of SSA involved on the top, back, and each side of the scalp (Fig 1) that is used in the assessment of the Severity of Alopecia Tool (SALT) score for alopecia areata (AA).1Olsen E.A. Hordinsky M.K. Price V.H. et al.Alopecia areata investigational assessment guidelines – part II.J Am Acad Dermatol. 2004; 51: 440-447Abstract Full Text Full Text PDF PubMed Google Scholar We have updated this figure (SALT II) to include smaller increments of scalp coverage to facilitate the assessment of hair loss: (a) where small patches of hair loss predominate, such as in AA or cicatricial alopecia; and (b) where only certain areas of the scalp are involved, such as in male pattern hair loss (MPHL) and frontal fibrosing alopecia (FFA) (Fig 2). This reflects incorporation of earlier figures published by Olsen2Olsen E.A. Female pattern hair loss.J Am Acad Dermatol. 2001; 45: S70-S80Abstract Full Text Full Text PDF PubMed Scopus (200) Google Scholar in 2001 and Olsen et al3Olsen E.A. Canfield D. Canfield W. Budris K. A novel method for assessing regional scalp hair density in male pattern hair loss.in: Van Neste D. Hair science and technology. Skininterface, Tournai (Belgium)2003: 251-254Google Scholar in 2003.Fig 2SALT II aid for determining scalp surface area more precisely. The SALT score, using either the original SALT I or SALT II, is determined by adding the percentage hair loss in the various areas of the scalp. With the addition of hair density, SALT II can also be used to establish patterns of hair loss germane to different hair loss conditions.View Large Image Figure ViewerDownload Hi-res image Download (PPT) To determine total and 1% SSA, we determined the head circumferences of 26 female [53-58 cm (mean 56 cm)] and 26 male [54.5-62 cm (mean 58 cm)] subjects. We then categorized the head circumference into small, medium, and large and measured the total SSA of 2 male subjects from each category. We used a conversion factor derived from these 6 male subjects to interpolate the SSA for the remaining subjects. The SSA results for all 52 subjects ranged from 607 cm2 (smallest head) to 842 cm2 (largest head) or an average of 705 cm2. In all, 1% of the SSA was approximately 7 cm2 with the sections of the SALT II diagram reflecting percentages of the total SSA, rounded to the nearest whole integer. These tools are analogous to the “rule of nines” and the palm plus 5 fingers used to determine percentage body surface area in various body regions in cutaneous lymphoma.4Olsen E.A. Vonderheid E. Pimpinelli N. Willemze R. Kim Y. Knobler R. et al.Revisions to the staging and classification of mycosis fungoides and Sézary syndrome: a proposal of the International Society for Cutaneous Lymphomas (ISCL) and the Cutaneous Lymphoma Study Group of the European Organization of Research and Treatment of Cancer (EORTC).Blood. 2007; 110: 1713-1722Crossref PubMed Scopus (1084) Google Scholar The new figure of the scalp can be used successfully to quantitate both total scalp hair loss or can be used specifically on one area of the scalp only, such as the central aspect of the scalp, to assess involvement of MPHL, female pattern hair loss (FPHL), and central centrifugal cicatricial alopecia (CCCA) or the frontal and temporal hair loss in FFA. Patterns of hair loss can also be defined with this figure for AA, MPHL, FPHL, CCCA, and FFA. Efficacy assessments can be done by noting the density in each of the areas of the involved scalp: for that purpose, we refer the reader to the method of combining region and density rating published on MPHL in 2003.3Olsen E.A. Canfield D. Canfield W. Budris K. A novel method for assessing regional scalp hair density in male pattern hair loss.in: Van Neste D. Hair science and technology. Skininterface, Tournai (Belgium)2003: 251-254Google Scholar We think this new tool will be extremely useful both in clinical practice and in clinical trials of hair loss. Given the new interest in treatments for AA, it is important to introduce this figure for potential use in Food and Drug Administration–sponsored studies for that hair loss condition in particular.